[Kindrox]

I have seen a few people speak nicely of recoil reducing stocks on a shotgun, and a few people point out that that with a surefire light is a bad combo, but a lot of people don't sound like fans of them in general.

I though I'd ask for the specifics of their negatives.

[Fred Fuller]

The stock tube is too fat to get a proper cheek weld- for me, anyway. If it displaces your eye from the proper place at the back of the receiver, it's a disadvantage no matter what good it does with recoil. Good gun fit, proper form, a good gun mount, intelligent load/gauge selection, added weight to the gun and a premium recoil pad will help manage recoil better than gimmick stocks IMHO.

lpl

[Bix]

Stability and cheekweld appear to be the main complaints in this excellent AAR:

http://www.10-8forums.com/ubbthreads/showflat.php?Cat=0&Number=72263&page=&fpart=all&vc=1

[ArmedBear]

It depends WHICH recoil-reducing stock.

The GraCoil has a long and positive reputation. It can be installed on just about any stock design.
http://www.graco-corp.com/gra-coil.aspx?CategoryId=18
http://graco-corp.com/shopping/images/gracoil.jpg

The Beretta Kick-Off is a very similar design to the GraCoil, but developed originally for waterfowl hunting, so it's protected from the elements (the innards are also not as pretty as the machining on the GraCoil is:)). It's been showing up on other guns, including range guns.
http://www.beretta.com/dati/ContentManager/images/catalogo_prodotti_imgs/riduzioni/92_medium_1_678P_160P.jpg

The Knoxx Specops is based on the M4 stock, which is inherently pretty crappy, designed for a general military issue no-recoil carbine and CQB. It's not the recoil-reducing aspects of it that give you no cheek weld. It's the stock design. For 50 more bucks, you can buy a cheekpiece for it... Should come with it if you ask me. There's just no way an unmodified M4 stock and a 12 Gauge belong together. But the recoil-reduction part of it works fine.
http://www.blackhawk.com//CatalogImages/18-1158-IMG1.jpeg

This design (JS Air Cushion is pictured) has reappeared over the years. I've seen it on an ancient ivory-colored plastic Model 12 stock, as well as on custom wood like this. The idea is for your cheek to stay stationary along with your shoulder, and the gun to recoil independently. I think it works. Haven't seen it (or similar) on a "tactical" shotgun, but I'm sure it's out there somewhere.

http://www.pacificsportingarms.com/admin/uploads/1168549605b_mvc-014s.jpg