As far as my knowledge of Trek goes, only the newer starships have quantum torpedoes:
Defiant, Akira, Sovereign, and Prometheus class starships.
Intrepids were supposed to have as well, but Voyager didn't need them for its first mission so never got them. Towards the end of the war, I heard Galaxy and Excelsior class ships were refitted to fire Quantum torpedoes.
Now for the Enterprise-E, Sovereign-class ships are heavily armed with both quantum and photon torpedoes. However Quantums are only fireable from the underside of the saucer where the Captains yacht is. Photons are in the engineering sections under the deflector dish and in the aft behind the saucer. You see the Enterprise fire quantums a lot in First Contact and the Troi scene in Nemesis, and you get a glimpse of aft Photon Torpedo fire in Insurrection and Nemesis. Forward Photon firing can be seen in Nemesis as well.
The Defiant only had quantum torpedoes as far as I know. Only Quantums were ever fired as far as I can remember in DS9. The Defiant also had one heavy phaser array in the dorsal section of the ship.
Yeah, I can't remember any Akiras ever firing Quantum Torpedoes.
I'd also like to point out that the USS Lakota, an older Excelsior-class vessel, was outfitted with a Quantum Torpedo launcher as part of its weapons upgrade and really could have put a hurtin' on the Defiant. I don't think the tech is restricted to just newer ships, but newer ships could perhaps be better equipped overall to handle it.
Lastly, in Tears of the Prophets, we see Quantum Torpedoes destroying a weapons platform early into the battle. It took three or four torpedoes, and they hit the platform one at a time, as opposed to two hitting at a time like the Defiant normally fires. Since the Defiant doesn't usually fire forward weapons one at a time, I don't believe she fired those shots. I really want to see what ship fired those damn torpedoes!
