This looks fantastic! There are cues from the Defiant of course, but consciously or not there's a lot of Jem'Hadar attack ship in here too.
My suggestion would be to make the bridge more circular (or at least ovoid) as a more Starfleet-esque design cue, the existing structure is fine but IMO reminds too much of a Dominion design. But who knows? Could be intentional that way.