I wish they fit my car too.
- Familiarity: I've put it through the wringer
these were made for gettin nasty on the mountain. they have big knobs that grip EVERYTHING, even our loose stuff in flag before the monsoon season. and the rolling resistance is minimal, at least compared to other aggressive tires. i don't know what xc tires feel like. they run tubless extremely well too. i haven't notice any leak whatsoever.
they're not the lightest tires, so probably not your xc raceday choice. also, on account of their stickiness, they're not the best with durability. that being said, you should still get a lot of life out of them.
i have the pacestar tread which is a little more durable and a little less rolling resistance. the trailstar is supposed to be more sticky, but i haven't found a need for it yet. maybe if you're cleaning gnarlier stuff than me...