Body roll is definitely there at high speeds due to the dimensions. But I haven't had any issue with Wheelspin past launch on the HEV and haven't experienced any in the 2.0 AWD.
As for power, they can do 0-100 km/h in 7-8 secs, so I wouldn't call that sluggish for a gasoline and HEV variant, but yes some of the initial torque is wasted on the HEV because the FWD setup can't utilize it.
The Hi4 AWD PHEV apparently has sub 5-sec 0-100 km/h and with performance tires probably can make full use of that torque.
From personal experience, I haven't taken the HEV beyond 160-170 km/h because I'm not confident in it's stability like I was with my C-HR, which I was driving prior to the H6. I could comfortably go over 180 km/h on that and it would still feel planted to the road. It didn't accelerate as quickly as the H6 so it felt sluggish in that department comparatively.