I have a Lehner 2800xl in my Ofna 9.5, it's far from slow on even just 12 matched GP3300 cells.

Here is a vid from when it still had the center slipper in it, and I blew my brother's 10-turn B4 away.....complete with both buggies wheelying! Oh yeah, and the weird noises are from the camera man, he's got ADD or something and always has to add some kind of "flair" to each vid. :D