Have you guys seen this? It's an utility that replaces default flight dynamics for helicopters. It works with R-22, Bell 206, EH-101 and AS350 (for FS9) so far. I've been testing this tool today, and I can't say if I like it or not. Flying 'feel' seems much better, but landing and take off is too difficult for me. It looks like ground effect is too strong.
I don't have any experience with real helicopters, I'm just comparing HTR to DCS: Black Shark, EECH and default FSX.
HTR simulates autorotation, vortex ring state, blowback and transverse flow effect, retreating blade stall, ground effect, wind, weight displacement and ground forces.