The Chatterbox units work extremely well when powered by their own rechargeable battery pack. They are not 100% waterproof and must be covered (I used a shower cap and rubber band) during periods of extended or heavy rain. They will withstand a light shower.
However, if you are hesitant about replacing battery packs during a full day's ride and are considering powering the Chatterbox units from bike 12v, DON'T!
You will have to make all your own cable sets using isolation transformers for every input. The Chatterbox units will absolutely fry your upstream devices if everything is powered from the bike.
For a solo setup, the Chatterbox works well. You cannot use two units (one rider, one passenger) without modifying the RF antenna of one unit to reduce "swamping". The modification voids the warranty of the unit and is not officially supported by Chatterbox.
In case you can't tell already, I've owned a few Chatterbox units. They were good money and represented reasonable value IMO. But if you are looking for a full-blown, bike (12v) powered, rider/passenger audio system... look elsewhere.
[/quote
Myself and 2 riding buddies have used GMRS X1's for several years and they work great! No problem at all with 2 units on the same bike. Rode "bitch" for 300 miles and we talked the whole way.