I've heard not so good on Gustafson and Targa. I've heard good on Rifle, Clearview and Cee Bailey.
I had a Clearview 25"GT with vent which I liked just fine, not so good for passenger.
I have a 29.5 Cee Bailey vented now, which works well for me, and better for the passenger. I do miss the convenience of the Gold Wing vent, though. Screwing around with pipe insulation is a PIA. Maybe I'll get around to putting the vent on, one of these days.