Well, have not put a tachometer to it but you can see it run in my garage:
http://www.youtube.com/watch?v=onmKTO1KG7I
and I have read that it moves around 8-10,000 rpm. There are a few other demos of this engine on YouTube and I believe one of them puts a tach to the .07 Gilbert (much faster). Again, this is with a 7-3 prop - the stock prop was a 7-4 plastic number, and I have also read that a 7-3.5 (if such a thing exists) would be ideal.
The issue for me is to find a profile C/L plane that uses an engine of this size - say, a .10 or so. I am not going to put it on a Jumpin' Bean - much as I like them, the wing area simply is not enough. I am not the most proficient at building from blueprints, so for me it would be ideal to build from a kit less than 10 years old.
Cent13