Re: The operational status of NCC 1701-A...?
If we assume Starfleet gave Kirk a dud, the "She's twenty years old!" exclamation regains full consistency.
If Starfleet wanted to reward rather than punish Kirk, they would have given him a Constellation (the obvious stopgap/insurance thing in case Excelsior didn't pan out - the same old, only now in duplicate to squeeze every last drop of performance out of the old hardware)...
Except the fact that the command crew were more familiar with the Constitution
class. We don't know what major internal differences there are between classes.
Self-appointed Knight of the Abrams Table! - Thanks Marsden!