The small gas engines have always been a bit tempermental for me. I flew the 3W 26, and while it put out a lot of power for its size, it was a pain to setup and manage. Clearly the smaller gas engines have come of age though, and it sounds like the OS 33 is a great choice.
Oh, and don't confuse a lack of response on your thread for a lack of interest. I've been following your threads for some time now, but haven't felt a need to comment as I wouldn't be adding anything to the discussion.