I think the DS9 era galaxy would whip the Defiant, but it wouldn't have quantums.

Ok. Time for a ST buff to give you the awnsers for this. The Defiant is a Escort/Warship. It has a higher Combat Strength than bot the reg Galaxy and the War Refit Galaxy. Here is some info.
Galaxy reg: Galaxy = 1,000
Beam Firepower : 1,000
Torpedo Firepower : 1,000
Weapon Range and Accuracy : 1,000
Shield Strength : 1,000
Hull Armour : 1,000
Speed : 1,000
Combat Manoeuvrability : 1,000
Overall Strength Index 1,000

War Refit:
Beam Firepower : 1,400
Torpedo Firepower : 1,000
Weapon Range and Accuracy : 1,220
Shield Strength : 1,890
Hull Armour : 1,000
Speed : 1,601
Combat Manoeuvrability : 1,000
Overall Strength Index 1,355

Defiant:
Beam Firepower : 1,400
Torpedo Firepower : 2,150
Weapon Range and Accuracy : 810
Shield Strength : 880
Hull Armour : 3,400
Speed : 955
Combat Manoeuvrability : 30,000
Overall Strength Index 1,560

As you can see the defiant has everything except the weapon accurancy and shield strength BUT its armour make way up for that. I have proven the Defiant rules. Though it cant destroy a Sovereign

Oh heres the Sovies stats

Sov:
Beam Firepower : 1,700
Torpedo Firepower : 5,700
Weapon Range and Accuracy : 1,260
Shield Strength : 1,700
Hull Armour : 1,900
Speed : 4,125
Combat Manoeuvrability : 4,000
Overall Strength Index 2,925

And btw The Defiant was originaly designed to combat the borg but when the borg threat went away they had no need for it so the just "stuck the prototype in storage". The the dominion came along and Sisko needed more defence for DS9 so he asked for the defiant eventhough it was massively flawed. It was way to overpowered for its size, they nearly blew the ship in half on its test run (they tried to fire all weapons at full impulse). and all my info came from http://www.ditl.org/

ah - after a long wait - there is someone with numbers.

Remember, the Galaxy (U.S.S Odessey) that got taken out in DS9 had no resistance to the Poleron weapons on the dominion bugs. Once the federation acquired a Poleron weapon to study and develop shields resistant to dominion tech a BugFighter was comparable in strength to a regular Bird of Prey! And remember the Odessey only went down because one of the Dominion ships rammed her. She was turning to flee, after hanging in there admirably. Imagine fighting 3 BOP's in a galaxy with your shields down!

Meaning a TNG era Galaxy with runabout support could have spanked the 3 BugFighters if it had Dominion weapon resistant shields (like all fed ships had after sisko captured the crashed BugFighter). A Dominion War refit Galaxy would have made it look silly.

Also In DS9: Defiant, the supposedly massively powerful defiant was quickly overpowered by a BugFighter wing, but once again when the shield tech of the federation was modified against Poleron weapons the superiority of the Defiant was clear.

Defiant is small, but like others have said, she is built for war, not studying gaseous anomolies and ferrying diplomats, which changes the rules for a fed ship.

If any of you doubt the calibre of a Galaxy, 5 of them in "sacrifice of angels" apparently accounted for 30 odd dominion ships (edit) with no losses themselves (/edit)! Imagine what the defiants can do in numbers..

http://www.ditl.org is a great source, even if a lot of is conjecture.

Oh, and the Admirals defiant off BCFiles is overpowered compared to stock ships imo, but whats stopping anyone opening the .py files themselves? I did and it's a much more fun ship to use now.

First post, hello!

One last thing... To quote Sisko (to the best of my memory at least) "She may have flaws, but she has teeth. And when the Dominion come through that wormhole, I want to be ready". He said something along those lines. I cant remember. And that bit about the Odessey and SoA is true. The galaxy is one of my top five ships, I think its a very good ship, one of the best. Hey atleast they dont die in one full phaser blast like Mirandas (namely the Seatack and the Magestic, the 2 ships that were with the defiant during the SoA battle but got destroyed). Yes I do know alot about DS9.

That's right, the Defiant is over powered for her size, meaning she has so much extra power left over after turning everything to max... they had problems modifying the cloaking to even be able to mask her power! Think about that, a device made to cloak a Warbird wouldn't work at first on the defiant cause it had too much power. Moreover, when you watch the defiant lay mines in front of the wormhole, it gets attacked by 3 bugs with its sheilds down... and what did the weapons do? Bounced off the armor :D. And of course, you have First Contact where the federation fleet had been fighting the cube for 3 days and ships are being blown up left and right. But, when the defiant gets shot, it doesn't do much, and when the defiant shoots, the explosion on the borg hull are bigger than that of any other weapon (phaser or otherwise) that is shot at it. And THEN you have the cube blow up and take out several ships with it just by the shock wave, yet the defiant still survived and could be repaired :P. And if this isn't enough, you have the episode where the breen disable the fleet. During the scene where they are arguing on the bridge, you can hear the defiant being pounded. It took a while to blow the thing apart even with no power, yet in the background you see unmarred ships get shot once and basically get totalled.

The power of the defiant increases as the show goes on. When it was first introduced, it was about the same as a galaxy all things considered, but later it becomes invulnerable to bug weapons O_o. And there's the alternate universe one that takes on a Neg'Var and wins. The defiant reminds me of the revolutionary war ships the americans had. The british had upwords to 80 gun battle ships, yet a small sloop like the Enterpise with only up to 16 or so guns could take them out. In the world of combat, manuverability is key, not firepower.

It sure can take a beating with no shields but thats because of the Ablative Hull Armour (aint it great). And also in First Contact its a 4 day running battle, not 3 day. And also I doubt the Defiant was there since day one because it would take it a few days to reach Earth (on DS9 they said it took a week), and I know it was the Typhon Sector that they were gathering the ships but that sector is not that far from Earth (on ST standards).

I meant Nine of Nines v1.5 defiant, not admirals. You could ram starbases with the original hardpoints. Had a mass many times that of a galaxy and so on.