There are more than one series of the .61 SuperTigre and there is not a bad one. I own several and started as a sceptic for some of the same reasons you mention. As you look at the 2 stroke cycle engines the performers are using a higher muffler volume in general. Look at the mousse cans and Mac's and the TH mufflers that are popular on O.S. etc. and you will see the silimarity in that big ST. muffler. While you can't argue the fact that you can have a higher displacement and more power for the same weight (sort of the curse of the .60 sized engines) the ST is an awesome performer, easy to tune, and they can last a very long time if cared for properly. Enjoy your new plane, Cliff