I got a Mk2 about 6 weeks ago for exactly the same reasons as the OP, and it’s been great at the local woods. Yet to take it to Wales, but it certainly feels very stable when the speed picks up and is fine over all the local jumps and drops that I attempt (they arent very big so I will probably put a bit more air on fork and shock when I head to Wales).
Re the shock, its a 38mm stroke so getting the 25% sag is tricky. 20% is 7.5mm on the shaft and 30% is 11.25mm. This gives a pretty different feel on the bike, but pretty difficult to actually measure. I beleive the Stage 4 has a 40mm strocke so similar issue.
Its not light, so if your definition of XC is racing, you might want to look elsewhere, but I see XC as long rides and its comfy enough for me for that.