On the other hand, I have had 3 On-one/PX frames and they have all been defective in some way.
First white Inbred - terrible paint, disc mount badly welded so had to hand file it straight (OO advised me to do this)
853 inbred - well known chainstay issue caused huge gouges in metal, sold mine quickly but my brothers chainstay snapped and he got Argos cycles to fix it with a properly designed chainstay. Attitude of OO was "ooh yes we know about that, maybe we should sort the problem out"
PX kaffenback - unable to use 11t cassette as chainstays designed/made wrongly.
My brothers C456 has had headset issues which were the fault of the design of it.
I bought their products as they were all I could afford but I will never again buy something from them. Now have a Specialized Pitch and a Kinesis road bike - the kinesis was same price as Kaffenbak was but is nicely finished, great paint and not a single issue to report. Spesh is the same.
My 1994 Kona Kilauea is better designed than any of the On-ones I've had.