I just picked one up a week ago. I demoed one first when I went to visit my brother in Georgia for about a 17 mile ride. I know then instantly that I was going to get one. I have about 30 miles on mine and I couldn't be happier.
My first ride with it I took it to a trail that has rock garden after rock garden. Those big tires just rolled right over them with abandonment. It was very confidence inspiring. The next trail that I went to I would say if it has one root it has 20,000 roots. Some run perpendicular some run parallel some run slightly of at an angle. It just laughs at them.
As far as ride quality goes it feels very supple. My other bike is a Breezer Lightning 29 steel framed bike that has one of those nice "steel" rides to it. I can't say that the Stache rides any harsher. The big tires take any edge of most hits and the frame has been designed very well with some compliance built into it. I have been riding mtbs since 1991 and this bike rides very well.
The geometry is amazing! It has a nice solid feel to it, as I said earlier, very confidence inspiring. The 68* head angle makes it very stable but the short seat stays makes it able to turn razor sharp. It turns just as sharp through the tight trails we have here as my 71* Breezer does. Only it is not twitchy feeling at all. I didn't think that my Breezer was until I hopped on it after riding the Stache. There is definitely some difference there.
You will need to get a tire gauge that reads and is able to adjust in very small increments like this one.
https://www.amazon.com/gp/product/B004XISIK4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
I'm about 235 in gear and hydration pack and so far I have been running 17# rear and 16.5# front but I am still experimenting with pressures.
All in all I'm very happy with my purchase. No buyers remorse what so ever. Right now is a good time to pick one up as they are on sale this week. I hope that helps. If you have any other questions feel free to ask.
Just to add if you test ride one at a bike shop and they air the tires up to 35# it will feel horrible. That is too hard for those tires.