I’ve had mine since March this year, it’s an X1.
The bike has been faultless in the 1500km it’s covered so far. Handles great, rides & climbs very well.
It is long, but I think that makes it good on the downs, you can get rear wheel slippage if you get too for forwards / out of the saddle when climbing, but that’s not a massive issue as it clims so well when seated / hovering above the saddle.
I don’t find the rear an issues on twisty single track as that’s what I ride a lot of round here.
Sometimes it has a dropper on it for more gnar, others it has the normal post on it.
I’ve raced XC, done XC marathons like the Dyfi on it and done whole day epics in Wales and the peaks clocking up 100+ km on it with no complaints or stiffness etc from the riding.
Highly recommend if you can get one