Out of the 70,000 miles or so I've flown since November of 1999, I think that I've been late a total of 3 times. Once due to storms at STL and on the East Coast, once due to bad weather at IAH, and once waiting to takeoff on a Friday evening at LGA. Not bad at all, and none of the horror stories of some of the other airlines.
I think that the Ambassador's club is extremely worthwhile, if for nothing else than the ease of check-in at a lot of busier airports. Since I almost never travel with checked luggage, being able to bypass the lines- either at luggage check (even 1st class check-in) or the gate saves a great deal of time. And yes, the lines can be long, especially at STL. The STL club is nice, though I too wish there was another located further down the C concourse. JFK, LGA and LAX clubs are also nice, and BOS and DCA aren't bad either. No free alcohol like the DL Crown Rooms, but decent enough for the price.
As for service in F, as I mentioned earlier, you may not get the "luxury" items of some other carriers, but still, for a free upgrade, not bad at all. I do feel that the majority of the FA's do try very hard with their somewhat limited resources. I had the chance to fly STL-OGG in F, and wasn't at all dissapointed. I'll be going to CDG later this year in full-on "TWOne" and am looking forward to that experience.
My favorite TW station is LAX- quite a professional and experienced staff- and the added bonus of 767s to STL at times. I think that most people who haven't flown TWA in a while will be pleasantly surprised, especially business flyers who expect to be treated professionally and get where they want to go. And Elite 1 and above levels are a great way to go- unlike bigger carriers, a lot of TW staff actually seems to value your business as a FF. Just the other day, when calling for one of the free, unlimited upgrades (try that on AA or UA), I had an agent say, "Let's see, you're an Elite 1. We love you..."