Thanks Andrew for the excellent write-up and for including my bike in this series! I've been enjoying all the min-max articles and ensuing comments. Good stuff.
Judging from the comments, it seems Trek (or someone else) would do well to introduce an updated descendent of the Stache. The bike is a bit of an anomaly for a big MFG (sliding drop-outs?!?) There was a moment when they introduced the Stache and the Full Stache that I thought 29+ would really take off - pretty sure I read somewhere that Rockshox made the Yari and other forks 29+ compatible largely because of Trek's commitment to 29+. Alas...
I've also been surprised that Surly and/or Salsa hasn't introduced a modern version of the plus bike. They were both pushing the envelope on plus sized bikes for a while, but the geo of the current Krampus and others is pretty conservative. I had a current generation Krampus right before the Stache. I'm not sure what aspect of the geometry made the difference, but I found the Stache way more fun than the Krampus.
+1 to the value of the XTR shifter. I actually bought this used from a friend 4-5 years ago! Maybe the only part that has lasted that long.
Thanks!