I didn't read through all of the posts here, but wanted to chime in on the Scala. I have had one now (the Team set) since early this year. I really like it. It has it's quirks, (somethimes locks up and you have to cycle power) but it's crystal clear and easy to use.
Now there's a new device that Scala has come out with that is really slick. It's a new mount for their system that has a 2mm stereo jack built in. With this, you can plug any stereo device into it; MP3 player, Sat radio, bike radio, etc. When a phone call comes in, it mutes whatever is plugged into it, so you can take the call. The best thing about it is, it is true stereo into the attached helmet speakers. The only down side is, it's not real loud. It uses the power from the device (not the Scala set) to play the music, so you use the devices volume controls. This is WAY better than the older stuff that was only mono. You can check it out on Scala's website.