Heh, its fun to be fought over.
I've never been on an A340-300. I've been on one of US's A330-300s, and I thoroughly enjoyed the experience. Same plane less engines, I s'pose... but I'm assuming the A330's climb performance is better.
That being said, I love the 777 and fly on it constantly DEN-IAD, IAD-SFO, DEN-SFO, etc, and used to fly it IAD-the rest of the earth... I prefer it to any other aircraft on those routes.
But I avoid 737s like a leper's touch... even the NGs. When the NGs came out I went out of my way to fly on 5 or 10 of them and I still prefer my happily little seat on a UA A320. Is it just me or do A320's land themselves MUCH more gently than 737s? Or is it the pilots? Hmm...
Heh safe to say that the polls and whatnot are more based on the airline's choice of interiors than the plane... as many people state millions of times, 3 out of 5 or so idiots think they're on a 747 no matter what widebody they're on.
I prefer the Envoy product on US's A330 to United's C class any day. But that doesn't mean I prefer the A330 to the 777 or vice versa... I just like one seat better than the other. And that's what most polls reflect.
(I like to root for Airbus cause they're #2... having a #2 improves quality in any industry)