Okay, just had my first Taca experience (SAL/SFO Jan. 1) and it was a mixed bag. This is a long post, but may help make clear the randomness of Taca and things to keep an eye on if you are traveling on them. This may be better under trip reports, but I'll put it up here first and see.
First off, my entire itinerary had to be issued on paper tix due to the one Taca leg (ORD/LAX LAX/GUA SAL/SFO SFO/ORD) which blew, but there ya go. I was not paying attention when I booked it and thought the whole thing was straight UAL metal. I was unable to obtain seats for the Taca portion ahead of time. When I called United, they said I needed to call Taca. When I called Taca, they said they couldn't give me seat assignments because I had paper tickets!

Their advice was to have someone assign them in person while in Central America. I was a little worried as this was the only leg we were not in 1st, it was the longest leg (6.5 hours) and I am totally unfamiliar w/Taca, but what do ya do? I made my calls, several times, and gave it the best shot I could.
Okay, so I'm in Guatemala City (waiting for my Pullmantur bus to El Salvy - very nice bus FYI) and I spot a Taca office. I head in and ask for seats...After scratching her head and fiddling with the computer for 20 minutes, she tells me that "United won't give us their passenger list until 24 hours ahead of time," and that I need to get seat assignments at the airport. Also, she tells me the flight is drastically oversold and I need to be there 3 hours ahead of time.

Okay, fine, doesn't seem realistic that they won't know who the "United" passengers are until 24 hours before the flight, but hey, I'm in Central America and there is a man with a semi-automatic rifle standing two feet away from me, so coolio, I'll get to the airport in SAL early.
I arrive at SAL 3 hours early and attempt to check in (with no checked baggage). I am sent, literally, to 5 different people who keep telling me I have to go to someone else with no explanation provided. I'm getting a little nervous at this point as my call to Taca earlier in the day confirmed that this flight was in fact, badly oversold. Finally, a very nice man decides to assist me and starts going through my record. He tells me that this is the first time this particular flight is a United codeshare and despite the fact that I am holding a ticket for this flight, I have
no reservation!?!!!!!!

and that the flight is oversold by 22 seats. How? How? I called Taca a dozen times, I called United at least that many times, I went to a Taca office in GUA!!! Why was I not told I didn't have a reservation?!!!!
He then tells me that he has to go downstairs and "work" on our tickets. At this point, I start babbling like an idiot about how I'm confirmed in 1st on all other legs, I'd really appreciate anything he could do for us, we would really love to sit together, how much I love El Salvador, etc. Keep in mind that I am running a raging fever and look like hell, thanks to getting really sick in Guatemala and despite the Z-Pack the embassy doc in El Salvy provided to me. He vanishes and we stand there for 30 minutes getting increasingly nervous. Finally, a woman walks up and asks us what we are doing there. I explain the situation and she says "He walked off with your tickets? What did he look like?," in a voice that strongly suggests we just fell off the mango truck. Now I begin to panic. I describe him and tell her how he was very nice, while she sits at the computer and begins to go through our record. She has "bad cop" written all over her, and begins tsking and shaking her head as she looks at our record. Just as I am beginning to think that we are totally lost and that some vagabond posing as a Taca agent has absconded with our tickets, the nice fellow shows back up with our tickets in hand.^
Good guy and bad cop then have a rather heated argument in Spanish. I speak just enough to understand that he was doing something for us that made her mad. She keeps telling him that he can't do it and he keeps trying to wave her away. After about 15 minutes of them arguing, he hands us 1st class boarding passes!

Yay!!!!! I proceed to "mille gracias" the poor guy into the floor and ask for his name to write a nice letter. He seemed really surprised that anyone would bother to do that, and gave me his name while bad cop sat there giving us dirty looks.
Other notes - very nice Taca lounge at SAL, more fun to hang out at the coffee bar by the Taca gates and eat yummy El Salvadoran sandwiches and chainsmoke though.
Onboard service was non-existant, one fellow yelled at the flight attendant after ringing the call button and waiting for 30 minutes for a drink refill. He said "at the prices you charge for this cabin, I expect better service." Truth be told, they were hiding, pulled the curtain to the galley and pretended like we weren't there. If I had "paid" for my ticket, I probably would have been ticked too. It turns out they had a cake upfront and were eating and having a party for someones birthday.

Other than that, seats weren't too bad, inflight magazine was dull & the meal (strange canned ham slices w/potato wedges and tasty fresh veggie mix w/a piece of cake) which was served in a tin tray, felt very tv dinnerish. They sold meals in a box in coach for $5.00 - sound familiar?

NOW I know why everyone brought Pollo Comparo onto the flight with them!
Would I fly Taca again? Only if I could not get on UAL. The awesome CSR really made a big difference in our experience - if we hadn't run into him, who knows, and the free 1st was a super bonus. That being said, the whole "no reservation" thing has me spooked a bit, and the lame service in general is a big deterrent. If I do fly them again, I'll make sure I have seats and a reservation ahead of time and will get to the airport really early, just in case.
Miles haven't posted yet, but I'll wait to panic until next week.