new Sram X.0 shifters. I'm going to be ordering my bike soon, and I'm not sure which shifters I want. I currently have the Sram MXR grip shifters, and I'm comfortable shifting with them. I don't know if I'd like the Rapid Fires or not as I have arthritis in my thumbs. The new Srams are supposed to be real good. Lightweight, durable and smooth. Anyone have them? If so, do you like them?