I am looking to go to the newest Shimano mtn bike rapid fire shifters. I really like the fact that they have a two way release. This allows the rider to choose between either using the thumb or the index finger.

Shimano's website is a bit confusing. I see the Saint SL shifters, and then the XT and XTR. Is the Saint an entry level? Is XTR still their top of the line?

Thanks!