We use the Scala Rider Teamset. Very happy with the product. I have a modular, and my wife wears a full face. When I take or make a phone call, folks can't tell I'm even on the bike... much less cruisin down a very busy highway! The noise cancellation is awesome. One irritation is the VOX-activated... sometimes the mics can be finicky, and you have to make a few loud noises to get it to kick on. Overall, the product is great. Speaker quality could be a LOT better, but they carry voice perfectly. They're not dynamic speakers enough, for music.
The Q2 is a good product for talking to other bikes. They've improved the current Q2, over the previous versions. More capable now.
Scala is going to offer the G4 very soon. That's what I'll be upgrading to. Can talk to several bikes at the same time, in conference-call style, where you hear each other. This is a big improvement over the other two previous systems, that only operated on 1 channel at a time. Also, the G4 will talk to several bikes, up to a mile.
Good luck in your decision.