I've used the EZ grip and the regular model they offer. After switching over to the EZ grip, I'm pretty sure it will be all I will use from now on. I've used stock CCM barrels, Deadly Winds, PE barrel and an Ultralight. All ran with no rubbing problems and I still had room. I also like the fact that with a flat surface on the handle I can throw skateboard deck tape for extra grip.
Try them all out if you can, if anything buy multiple ones, try them out then sell what you don't like.
Here is my 6.5