I have a mix of xt, deore and raceface drive train. To be honest it feels rubbish compared to the 10×3 XT kit on my mates ride. I’m going for the XT groupset from actionsports.de! Had SRAM X7 on my last bike and it wasn’t as smooth but worked very well.
Looking at the 2 Canyon bikes you mentioned, I would go for the XC8. You obviously want something more XC oriented rather than one of their AM models. The XT makes for a lighter bike…
The good thing about Shimano kit is that you can pick it up pretty cheap. The downside I have found is that it takes a little more looking after. I find that I have to tweak my gears before a ride.