Yes, too tiny props to reach 30krpm, but they also talk about 21900rpm on a APC 5.7x3 (with 5% nitro), and that's pretty good.
It would have be nice to see Profi and Fora make something a little more sporty in the 1/2A class. I've been tempted to get the 2.5cc RC Junior, it is a little large (for me) but it certainly looks great ;