I’ve just finished a very small batch of the XT 6 speed cassettes. I create each one from modifying stock cassettes and fit them to a King single speed hub. Here are some pictures of one on a frameset I’m building up. The new Shadow XTR derailleur is very low profile. It delivers a dishless wheel and a good chain line with a 17-34t range.

Someone asked recently “What is the deal with the front chain retention device? Do you think it is necessary with only a six-speed spread?” Well, it depends on how rough you ride and if you are willing to risk losing the chain. I use one. This is a Rohloff chain guide that I modify for some of the bikes I build.