My experience on US somewhat agrees with the OP. Over the course of 8 weeks late last year (2011), I flew 16 (SIXTEEN) transcons on US, roughly half with connections in PHL, half in CLT. With the exception of the general surly attitude of employees in PHL (and the annoying shuttle bus from E to the B/C gates), the customer service interactions have been pleasant, they’ve been nice in making seat changes and trying to keep an empty middle next to me, Zone 1 boarding, efficient overall boarding, and courteous flight and cabin crews.
Of course, the downsides are also there—no E+, no IFE at all (but I like having inflight wi-fi!), the credit card sales pitches, etc. – but customer service has been good.
In fact, on a few of the transcon sectors, I was upgraded to FC based on being a *G, but my understanding is that that was in contradiction to the rules, and was done out of courtesy by the checkin staff at my (small) departing airport.