they had delayed construction of the new battle fleet because the threat was 'less urgent'. Which was a stupid response if you ask me.
I'd say it was pretty smart - because any weapon devised against the Borg is only good for one or two shots, and any massive building effort thus is grossly misplaced. To beat back the Borg, you need to be constantly building new defenses, not betting your survival on something you built six years ago.
The Defiants weapons were certainly effective, and it was stated to have been originally designed to fight and defeat the Borg (techs that likely gave it the necessary effectiveness against Dominion tech).
Hmh? In ST:FC, the Defiant seemed to be doing squat to the Borg vessel, despite trying real hard. Apparently, she was as much a failure as Starfleet had feared...
I would surmise that SF in Admiral Janeway's timeline managed to 'shape up' in the 16 years it took Voyager to reach the AQ, and 'adapted' in a sense that they started shifting into a sort of overdrive - which also explains how a refitted Nova would also turn out to penetrate shields on a Negh'Var class ship.
I wonder... Would time travel of the sort performed by Janeway be so commonplace at that time and age that it could explain the leaps in technological progress? That'd be a relatively natural way for the (already verifiably time-traveling) Federation to get the drop on its opponents.
Timo Saloniemi