For the cost... I was disappointed. With tax and whatnot, it was nearly $300 to replace the stock $130 3.3. I don't think it was $170 better than the 3.3. A bit stronger and more reliable to tune, yes. You have to remember, I'm comparing it to a revo with an LRP28 in it. Now, that thing has some grunt. LOL! I'm not sure I'd spend the $300 on it again. If it was $200 or even $230 ($100 more than the 3.3), then I wouldn't bat an eye. To date, it's the most expensive engine I've ever bought.That revo has some snot! I know you said you weren't overly impressed with the .21 but it looks like it's doing pretty good in the vid!
That said, now that I have it, have the trans full of RRP steel (another $100) and don't have it over geared, I do enjoy running it. I guess I just expected it to have a bit more low end grunt. I think it's running better now than it did last time I ran it as it's wearing in more. It's a fairly new engine and starting this season, it probably only had 1.5 gallons through it. I've put half a gallon through it this year already. Seems a bit more snappy than I remember.
After checking out my 21TM thread, I forgot I bought it on ebay for $250 shipped. That's an easier pill to swallow at least. lol