I went to a local guitar shop today after reading on their website that they just got a shipment of new modulus basses. I was thrilled since no other shops around here stock them. So i went up with my friend who's also a bassist and checked out what they had. They had 2 5 strings: a flea bass and a quantum. I normally play 4 strings, but that didn't upset me at all. I plug in the flea bass first and the playability and tone were excellent. so crisp and agressive! my friend thought it was killer too. The quantum wasn't much different, other than the looks. They were both way over my head pricewise, but it was quite fun to try them out!