I have the Avon's without the throttle boss. Had them since the 1st weekend in September and really like them. Take that with a grain of salt though the only other thing I'd used any amount of time is the factory grips.
I just got the Avons with the throttle boss. around town, I HATE the throttle boss....it gets in the way, but of course highway, much easier on the hand.....to each his own, Im still glad I bought them, very comfortable...
As I mentioned above I got a pair of the Air Cushion installed around the first of September. Love 'em.
But about a Tuesday I noticed the chrome was coming of on both sides. I called the company Wednesday and the person that answered the phone was able to help me. She knew there was a problem with the chrome on some of the grips and she FedEx'd me a new pair which i received Friday.
You really can't ask for better customer service than that.
She also told me that they have changed the vendor they use for the chrome.