Chances are that you were on one of the A320s acquired from Braniff. I have flown on those a few times and they are very gross. You can tell the Braniff planes because of the different, multicolored, seats and different tv screens in odd areas. I would agree that those are pretty terrible. But the A320s that did not come from Braniff I find to be in pretty decent shape. No real harsh complaints about those. Not quite up to the standards of like a new DL 737-800, but much better than an AA MD-80, DL Md-88, NW A320 (how they get away with no IFE on domestic planes is beyond me). I have always had good experiences on those. But the new A320s with the all leather cabins are phenomenal. Some of the nicest domestic planes in the sky imo, sans jetBlue A320s. I have always really enjoyed my flights on those as they are immaculately clean, have the ife, and are extremely comfortable. Rule for A320s in HP fleet is to stay away from those Braniffs!! They are nasty.
But all of the A319s in the HP fleet I also find to be nice. Always very clean from my experience, with no pen marks, no broken seats, the adequate ife. No complaints on an A319 I have ever flown on, and those are probably the planes that I am on the most. Even without leather seats I would take it over a WN 737 because they are in good condition, comfortable, and have ife.
737s....yeah those are pretty bad. They generally are on pretty short flights, so it has never actually bothered me or been an issue for me, but they are bad. Hopefully that new aircraft order comes sooner rather than later to replace them.
And for as much crap as the 757s get on here, I really don't have as bad of complaints. The one I was on PHX-DCA last June was not necessarily great, but it wasn't terrible. Yes it was old, and worn, but it wasn't actually dirty or in total disrepair. The seat next to me was, actually, slightly broken where the seat reclined far more than it was intended to and I could tell the man behind that seat was pretty POed...even though he kept it to himself and only huffed occasionally and tried to push the seat up when the person next to me got up to go to the bathroom. But it was adequate and i was perfectly comfortable so I can't really complain too much.