A few years ago I figured I should check out 11sp since it had trickled down to SLX level. At that time the cassette was the only item I could get in XT for just a hair more than SLX, so I did so. SLX derailleur works great and has held up well. Kinda wish I'd splurged on XT shifters, as the SLX feels a little flimsier to me.