Someone I know reviewed one for an online mag called Totally Active. Erm, here I think.
He really liked it. It was in 650B mode with fat, fast Panaracer gravel tyres on it and keeping up with it on a cross bike on anything other than smooth tarmac was difficult. It was the wrong size for me, but it looked nicely designed and detailed.
That said, as the owner of an On One Dirty Disco that cost me 400 quid for frame and forks brand new from Planet X on eBay, it seemed expensive to me and you kind of know it’ll end up for sale at half the current price some time in the next 12 months. Depends on whether that bothers you I guess.