I have been considering buying the Helios for several weeks now. My LHS just got some in and after playing with one for a while I decided to stay with my M8. The Helios felt really cheap. Cheap plastic, cheap nobs and buttons and scroll wheel. Nothing on the radio felt solid...at least compared to my M8. The Airtronics unit just felt much more solid and better built, plus was much more comfortale for me to hold.
Just my 2 cents...