I think that the Shimano XT line provides excellent bang for you buck. Strong, relatively light, and really solid performance. It's a great workhorse line, at a price you can generally stomach. I was only disappointed when I realized I couldn't adjust the tension on the clutch mechanism. (Edit- clutch is adjustable, see comments below). Even with the clutch engaged and proper chain length (on a 1x10 Ibis Mojo HD) I wanted to tighten things up to prevent chain slap that was still occurring over really rough descents. On my newest bike I threw down on the XTR Shadow Plus on which you can adjust the clutch.