I have a Non-Pro Icom and having gone through an SM-6 - SM-8, SM-10 (not bad at all) and now with the Heil iCM, I can easily recommend the Heil. Great reports on audio and easy to set up using just the mike controls in the radio. And for $120 (often less from the dealers) it is hard to beat.
Just make sure you get the iCM which is made specifically for our type radios. http://heilsound.com/amateur/products/icm/
Clint - W5CPT -