The sound quality is impeccable. The two 12V custom Rock the Bike batteries keep the speaker thumping for 4-8 hours depending on how loud I turn it up.
The speaker is very portable. At 36 pounds it is a bit heavy, but I have carpooled with it and have never had a problem fitting it in a full car.
The only problem I have ever had was when a friend plugged in the AC power while the batteries were plugged into the Nutrix connector.
I highly recommend the Rock the Bike modified JBL Pro PRX series speaker to anyone that wants thumping bass and high fidelity sound in a highly rugged bike tour worthy speaker.
-Joey