The trip is done and I can share my views as a first time TAP flyer.
Booking the flight / Online experience
Booking our flight was a miserable experience. Wasted probably two hours to do simple task. As mentioned in earlier post, the chat agent told me not to put my US frequent flyer number and that did the trick. Few days later I had to follow up to add our United numbers to the reservation. That is absolutely unnecessary and pointless. Apparently it's a well known bug. Why they can't fix it if it's happening on a daily basis? Online experience was poor at best.
Put a bid for LIS - SVQ flight for $70 per person, few hours later the bid was accepted.
Checked in online around 8am for the 10pm departure. Got automatically assigned emergency exit row and seats 22A and 22B (I don't know if that had anything to do with my UA *G status). The second flight got us seats 3A and 3B. Online checking went smooth.
IAD Airport experience
Arrived at IAD airport and queued Premium line to check our suitcase. The check in lady printed our boarding passes. I've inquired if TAP is part of the TSA Pre. She said that they are but I didn't provide the number during booking. However she can put it in now for us. She said that she sees the numbers and it looks like I put them in the wrong place. She told me that next time I have to put them into Known Traveler Number field not Redress field. I'm 100% sure that I put them there (been using GE since the very beginning of it's existence and never had that problem). Anyway, after she put the number in, the new boarding passes had our TSA Pre on them. She told us that we can use Lufthansa lounge which is directly across the TAP gate in terminal B.
Also, she did not put Priority tags on the suitcases (ours or the people in front of us).
We went to Turkish lounge as the food there is waaay better than Lufthansa's selection.
The boarding was split into Premium and General Boarding group. I actually liked that.
TAP Inflight experience IAD - LIS
I was happy with emergency exit row, but my wife wasn't

She was cold the entire flight. I was happy that I could stretch my legs.
Flight was delayed by approximately 30 minutes due to the late arriving inbound flight.
22A
As for the in flight service, I'm used to United's system where they serve you a drink and then they follow up with the cart with meal and another drink service.
TAP had only one run with meal and drink of the same cart, and the cups that they are using are about the same size as the ones that your dentist is giving you to rinse your mouth after the procedure. One run would have been enough if the cups were little bit bigger or at least they would fill them up (not just half way through). One sip and your water is gone.
The meal was not bad. They had choice of chicken or pasta. We've opted for chicken. After the Turkish lounge we weren't that hungry, but ate it before shutting the eyes for most of the remaining of the flight.
Chicken meal
I really don't remember what they were serving as a pre arrival meal, but it was something in a small box.
Despite the late departure, we've arrived on time at Lisbon.
LIS Airport experience
After reading numerous horror stories in here about passport and security checks at LIS airport, we rushed to catch our connecting flight (we had 1.5 hour).
The airport monitors did not show our gate yet. It was our first time at LIS airport and we kept following the signs for connections. It was kind of confusing at first where to go. Then I saw probably thousand of people waiting in line behind the glass. Panic mode was activated. Our boarding pass was showing "Entitle to FAST" so I had a hope that there was some other line for the passport control and that we can make our connection. Got to the end of the hallway and saw 4 windows for passport control. Nobody was in front of us. We were through in 1 minute. Then I realized that we were in Schengen zone already. Heart rate dropped back to 70bpm. I figured that the people in line behind the glass are going out of the Schengen zone. Went to the lounge which was packed. Managed to grab two seats. We were monitoring the gates display tv and about 30 minutes before boarding time we saw our gate assignment. As it was showing 10 Minutes To Walk, we left the gate 10 minutes before boarding. Took the escalator down, crossed the food hall and... we were at our gate. Why they are displaying 10 minutes walk if it takes less then a minute? Anyway, the gate area was full. No place to sit. Flight was delayed 15 minutes (waiting for the cleaning crew to finish - that's what they've told us but we saw mechanic fixing the rear door). Boarded again with Premium. Got stopped in the jetway. Stood there for 30 minutes before we were asked to go back to the gate area... About 30 minutes later the boarding started again. The guy that was standing in front of us, told us that this year alone he got 6 or 7 times 600 Euro from TAP just for the delayed flights and what we see today is practically normal occurrence. We wouldn't mind, as that would pay for our entire trip and then some
Flight to Sevilla was uneventful 45 minutes hop with some food served (not expected but welcomed). My wife wanted to try Port but they only served coffee, tea, juice or water up front.
3A
SVQ Arrival
Arrived at the Sevilla airport one hour behind the schedule. Followed the signs to the baggage claim 8. Despite lack of the Priority tag on the suitcase, our bag arrived on the belt fairly quickly. On the way out we got 'randomly selected' for the baggage check by customs. On the way to the search table the gentleman asked where are we coming from. I've told him Washington DC, and he immediately told us to leave
SVQ Departure
The day before our flight, I've checked in online. I saw that our Global Entry number is entered in Known Traveler Number and in Redress fields. Got automatically selected 3A and 3B for the short flight (bid online for $60 per person accepted 2 days before the flight) and on the LIS IAD leg we've got 18A and 18B. I've got the short end of the stick and my wife got window seat this time

We left hotel at 4am and arrived at the airport 4:15am. TAP opens check in desks at 4:30am. This time the lady tagged our bag with Priority tag. Went through security and had 2 hours to kill at the gate area. Boarding started on time, but when everybody boarded the captain told over PA that due to the ATC traffic in Lisbon, our flight will depart in 30 minutes... That's 3 for 3 so far.
Shortly after departure we were given light meal.
3A
LIS Airport experience
Arrived 30 minutes late. The flight attendant was telling some passengers up front that if we get remote stand, some of them will have to really run to make their connection. Thankfully we got a gate. I believe it was the same one which we departed from 5 days earlier. Again, panic mode on. This time we saw automatic passport gates. Absolutely no line at 7am for connections. It took us 2 minutes to pass them as couple of the gates didn't work and we had to queue behind other people to use the gates which opened for them. Immediately past the passport control I saw TAP lounge. Again, I've inquired if there are any security check points before our gate to DC. The lady said no more checks. I was very confused as why people were complaining about 4 hours long passport checks at LIS airport.
I guess is it for arriving or departing passengers from Portugal? Lisbon connection is much easier then let say Frankfurt airport.
The lounge was tiny and almost up to the capacity. Every few minutes the lounge attendant would come and count the empty seats. Capacity control?
About 30 minutes before the boarding we decided to walk to the gate. There were the usual US bound questions to all the passengers where they put sticker on your passport.
Gate 42
This was the only on time departure in our trip.
TAP Inflight experience LIS - IAD
On time departure, and lunch service after 1 hour later. I did not take a picture and I really don't remember 100% what was being served. I think I had fish with mashed potatoes and veggies. Again, small cups for the beverages, but this time the crew proactively was walking with Coke or water 4 or 5 times between the meals. The pre landing meal was pork sandwich and brownie. I was surprised that they don't have a choice, as many people would decline pork. I was happy about being give port once for a change on a plane.
Arrived on time. Passed immigration within 15 minutes of landing and our bag came on the belt 2 minutes later.
Based on my very first experience flying with TAP, I would definitely take them again. Their biggest problem is IT. For $500 and $130 in upgrades I think I received good value for the money.
Sorry for the long rant, but I thought I would share my first experience with TAP.