I’m a bit late to add my 2p as you’ve ordered already, but for the benefit of anyone googling in future.
I have a 29+ I had made up by Waltly. It runs rigid forks in the winter and Fox 34 in the summer (non-boost, Bomboloni on farsports 35mm fits fine).
I’m only 177cm so just on the border-line of 29×3 making sense. Running carbon 35mm rims keeps the rotating weight down so it’s almost as fast as my Yeti ASR on my usual 28-minute (-28:30) XC lap.
Grip is superb as mentioned but get yourself a consistent gauge as the tyres are very sensitive to pressure. +/- 2 psi will see you pinging off everything to rim striking. Definitely go tubeless as you will strike your rims unless you run absolutely too high pressures. I guess a wider rim would make them less sensitive but that’s based on maybe rather than experience or science.
Good choice on the Stache. My friend has one and the rear dropout assembly that allows you to pull a 29×2 in even tighter is something I envy. If you’re building to their rigid fork then you’ll be able to swap to a Fox 34 if you want as I think their rigid is 15×100
If I was building again I would have gone for something that takes 27×3 and 29×2 but if you’re tall then the Stache is a great bike.