TC,
Beg to differ: maybe with the small tail rotor, but the 206 with the later tail rotor is quite manageable, and we operate frequently hot and high.
I'd be making more of an issue of the EC120's low inertia main rotor system, and the R22-like autorotation characteristics
I'd have grave reservations using an EC120 for low level operations that wouldn't cause any concern in a 206, because I'm not sure that I'd get away with a survivable auto. Apparently the factory pilots prefer to run on around 40-50kts in the 120, maybe for a good reason!