If there is a more appropriate subreddit for this, please let me know.
My experience flying US Airways:
I was booked to fly out of Westchester airport for my summer vacation in California. I get a TXT message 5 hours before the flight that the flight was cancelled because too much congestion. Not a weather problem, they just booked too many flights or over-booked the plane. Said the next flight wasn't until the next day. But they re-booked me out of Hartford and said my departure flights would be upgraded to first class as fair compensation for my inconvenience. Hartford is a lot further away, but I figured it was acceptable.
So I get to Hartford and am told that my flight will be delayed 30 minutes because of weather at my lay-over destination and as a result I will likely miss my connecting flight. So they just cancel my seat and tell me to go home and come back tomorrow. I was pretty pissed about this and told them that I'd rather go and take my chances that I'll still make my connecting flight because I figure that will be delayed as well. They say fine, but then tell me that my seat was down-graded to coach, not first class. I ask why and they said they already cancelled me before talking to me and they had to re-book and re-sold my first class seat. I explained that I had my boarding pass and that I was on-time for my flight and that it was a load of shit, give me my damn first class seat. Their response was that they can do whatever they want. Pissed as I was I got on the plane. A flight attendant heard me bitching to the gate attendant and decided to let me ride in an unused first class seat anyway. Gate attendants had no reason at all to deny me my first class seat, they were just being assholes.
So I land in Charlotte and (no surprise) make my connecting flight just fine. But the same issue at the gate. Despite my boarding pass and that I am on time, the tell me my first class seat is gone. So I'm losing it at this point but get on the plane anyway. Same thing, flight attendant sees me bitching and gives me a first class seat that was available. Once again the gate attendant was just being an asshole.
My return flight was on the red-eye out of San Francisco, no issues there, but my connection in Philadelphia not so good. I have a short connection window so I run at full speed to the next gate which is like 2 miles away. I get there, out of breath and I am at the back of the line. There is a man in a wheelchair in front of me. The flight attendant asks if I am with the wheelchair guy and I tell him that I am not and he tells me to wait there. So he brings the guy in the wheel chair onto the plane and comes back and tells me I cannot get on because I am 2 minutes late. I asked why the wheel chair guy was able to board and I wasn't and he said they made an exception for him, but not for me. I'm like "I could have just walked behind him and took my seat, I don't understand the issue." So the gate attendant says "You no longer have a seat available. Sorry." I look at his computer screen and there is a diagram of the airplane seating and I can see that one seat is still free and it's my seat. I point to it and say "look, I can see there is a free seat, just put me on the damn plane." And he just smiles at me, changes the screen and tells me to go away and rebook for another flight.
I eventually make it home on another flight, but I just cannot understand how this airline can still be in business if this is how they treat their customers. I contacted US Airways about this before ranting here and their official response is that they are sorry for the inconvenience. I'm sorry US Airways, but that just isn't enough. You failed to give me what I paid for and I had to fight with nearly every gate attendant just to get on the flights for which I was booked. You nearly ruined my (only) vacation this year and inconvenienced me and embarrassed me at every step.
tl;dr: US Airways gate attendants tried to screw me for no good reason 3 out of 4 flights.