I too use the 94357 for throttle, but I use the Fut 9550 low profile servo. So far, I have three (on three cars), and one of them is three years old. Not as fast as the JRs that SerpentD mentioned but works great for my driving style and cost only $75. It is a low profile (less weight) servo that fits nicely in the G4s.
I had a defective brand new 9550 that would just stop turning for no apparent reason, then it would work again. I sent it in for service and Futaba said they would replace it with a new servo. The 9550 is now discontinued and will be replaced with the 9551 in late Oct, early Nov. It is the same low profile servo but I think the specs have been improved.