We've ridden both the 26er and 29er versions of On- One's fork and we like them a lot. The 26er feels a little harsher over the bumps than Pace's RC31, but that's not really surprising because it's a bit heavier. The construction is carbon composite legs pressed into the hollow-forged and machined crown.
For the big wheeler fans, the On-One is probably the best fork on the market, simply because the use of a different crown produces a longer rake/offset, which is a solution that should probably become the industry standard.