Boiler,
I'm trying to understand what exactly your complaint IS. It sounds like the pilots kept you informed and was pretty darn honest. Is your complaint about a mechanical? Sorry friend, that is going to happen on occassion....even precious Keep Delta My Delta has mechanical delays.
Is your complaint that the connection wasn't held 10 minutes for the 12 customers? Unless it was the last flight of the night, connections USUALLY aren't held.
My concern. Why do you find it acceptable for there to be a delay for weather but not a mechanical? Do you think these million dollar aircraft never break down? Mechanical delays are rare but they happen.
It sounds like you went on and on trying to find why you are upset when it was 4 paragraphs later...you weren't put in first class on your reassign. Did you PAY for first class or an upgrade. If so, simply ask for a refund.
Sorry fella, you may not want to hear this, but you have no complaint and in this case US Airways owes you nothing. The best thing you can do is shred the letter. You said NOTHING about not being communicated with. You said NOTHING about nasty agents or flight attendants. You said NOTHING about not getting to your destination. You mention NOTHING about failed promises by any staff. If just ONE of items were mentioned, I would be behind you 100% and give you a list of compensations
BUT
Your last paragraph tells it all. You want SOMETHING for NOTHING.