My experience is very similar to Gary Edwards'. Having flown a few differently equipped Lancair 235 aircraft, I am perfectly happy to have a high-compression O-320. It has well over twice the climb rate of a similar airframe with an O-235. Like Gary, I need much less room to takeoff than to land. 3000' of pavement is a comfortable minimum. On smooth grass, the runway could be shorter, as there will be more drag on the landing roll. 

Also, the O-320 properly set up is happy to fly LOP, down to about 6.5 to 7.0 gph. 

Personally, if I had a 235 with an O-235 engine, I would sell it and buy an O-320.