Hi JTAYLORPCS, I've submitted my Defiant ideas (garrett66666) at the google site. Just giving others here the opportunity to chew on these thought.
I'm just thinking that the modders here can stick to canon by giving the ship it's combat power/speed/high armor, but not giving it any abilities (which according to canon it should not have anyway). I've never seen the Defiant have engineering transer warp power to weapons/shields, or conduct high end diplomatic negotiations onboard, or have advanced sensor pods installed, or merge shielding with nearby friendly ships.....things all the other classes of Fed Capital ships have done.
The Defiant class doesn't even have the reactor to power most abilities anyway. The ship has a tiny reactor compared to other Capital Ships.
The Defiant could also have low hull points (smaller ship) and reduced rate of fire/shield recharge (small reactor).
As for Micale456's comments about the Defiant's 'abilities' (big guns, big engines, new armor)....well, they AREN'T abilities. The Defiant is packed with its weapons, engines and armor ALL THE TIME!
Hmmm, using the ship's specs, and lack of power/facilities for special abilities, it seems that this ship might be better suited as a Heavy Cruiser than a Capital Ship.