Having owned a .46fx, I can say that it's a fine engine. Up until this season, I'd have recommended it. Anybody who recommends it hasn't owned an Irvine.

I picked up an Irvine .53, and it has really blown me away. Ran well right out of the box. Never had deadstick. Gives me great veritical with my Ultrastick. I've never had a glow engine run so reliably, and in such a user friendly fashion. It's also pretty powerful. Usually with 2-stroke glow engines you can get 2 of those 3 qualities, but the third lacks. Powerful and friendly, but unreliable. Reliable and friendly, but not powerful, etc. The Irvine is all of them, and is tops in all the categories in my experience. The FX is good, but compared to the Irvine it is merely average. My next 2-stroke will be another Irvine.