Luke,
Ok, what do you base your opinion about OS engines on? Using the horsepower numbers put out by each manufacturer the OS 61 FX has more power output than the Irvine (not sure why you keep calling it the "powerhouse") 61 engine. The Irvine engine puts out 1.7 HP while the OS puts out 1.9 HP. You can find these numbers on the following links:

Irvine engines specs: [link]http://www.justengines.unseen.org/irvine.htm[/link]

OS engines specs: [link]http://osengines.com/engines/fx.html[/link]

Ken