Anyone using AA rechargeables in their grip?

I don't have the D800 grip, but when I first got my D300s grip I tried it with Sanyo Eneloops. I would get 8fps, but then after awhile I would notice it slowing down. I'd have to slide the battery tray out and then back in for it to go back up to 8fps. As the game went on it happened more and more frequently. I don't know if it was a fluke with my Eneloops, how I shoot (I turn the camera off a lot), or if other people have had similar experiences. For me it was frustrating and I sprung for the 4a and charger.

You can always try it out and if it ends up inconsistent like mine, just use the Eneloops in other things like flashes and Pocket Wizards.

EDIT: It looks like maybe my AAs just were just running low since someone said his get 400 shots. I probably would have needed 2 sets for a game. Without 2 trays that would be kind of a hassle unless you have nothing else to do at halftime other than changing out 8 batteries.