I have the 30G and love them. They have great noise canceling and they take AAs. Also, when you use rechargable batteries the battery meter can tell when they are about to die and flash red on the led.
The cell phone interface is just amazing. I have had to use the cell phone a .... few times.... in the air to talk to disbatch. Such as the weather closed down where is good to go or where can the truck the cargo....or we aren't gonna make the destination...where is cheap gas. When I call...they can't even tell I am flying it quality is that good.
Also, the music interface is great!
Overall I am very happy with the 30G.
Wankel