I bought an Evo to try. Doesn't have nearly the power it should and is hard to tune. I have read that some run great out of the box and some never run right. So far mine is in the later group. If you want easy to start, run, adjust, reliable and great power go for the OS 46AX. I bought one to compare against my trusty 46FX and the new version has a bit more power and has a smoother idle. Not that the idle wasn't good on the FX, the AX version is just better! I also have an ASP Super series 52 which is an impressive engine but it does some finicking around for several flights and a longer break in time. Once its loosened up however its easy to tune and the OS 46 engines can't touch it in terms of power. [8D]