I've used the Jeff Stryker dildo a few times (I think it's 10"x6") and it was intense. I had to warm up quite a bit with a smaller one first, and honestly I prefer the smaller ones (7"x5-ish)...I can hit my spot a lot easier. But the really big ones are good for those times when you feel the need to get extreme.

The thing about anal for me is that I can come a lot, but it's not as satisfying as coming via sex/bj or j/o. Usually after anal play, even if it was a 60 minute session, I'll still have to j/o to really feel satisfied.