Aresti,
Have you tried the GMS/Tower muffler? It makes quite a difference. Of course, I think I got pretty lucky with my FX. A go-fast guy around here stuck a tach on it and seemed pretty impressed.
That being said, a little more power would be ok.
On those hot days I could use it.
Maybe 30% nitro?

You are dead on about its size being tricky on advanced routines.
Sportsman is no problem, but higher up, Yeah.
Then again, for $150 plane and $100 motor, who can complain?

Now if Great Planes could find it within its heart to do a 72" X 72" Venus and keep it light for the same price point as their Giles 202?
MMMM yeah!