AndrewSwitchwrote a review of Continental X-King Tire - 29in on June 29, 2015
Familiarity: I've put it through the wringer
I got a set of these as a gift during the winter. They set up tubeless on KOM i25s fine - I did need a compressor to seat them, but they seal well enough to inflate from zero with a floor pump.
Initially I was a bit underwhelmed. They don't have great traction when it's muddy. I know it's not a mud tire, but other manufacturers' full knob XC tires have been more versatile for me.
As conditions dried out, I started to like these tires better. Not that it's that challenging to make a tire that grips well on hero dirt. I do like the volume, although the 2.4s only measure 2.3" on my rims. One thing that's very odd to me, though, is that the carcass actually measures wider than the widest measurement I can get over the knobs. At 550 miles, there's quite a lot of wear to the rear sidewalls, and the cords are working their way out through the rubber. The tire has also been weeping sealant a little bit, though it's still holding pressure okay. Finally, I'm tearing the corners off some of the knobs, and undercutting them some.
I won't be buying another set of these - I think the tread on a mountain bike tire should protect the sidewall better than that. They might sit a little better on a narrower rim, though.