8.5 - 10 lbs is typically the sweet spit for my 5s, but i can't deny the Spector Euro 5 RST at 7lbs even. That thing is nice to your shoulder. That said, with a good strap I can go all the way up to 11.5 lbs for up to 2 hours.I have 12 currently. All weigh between 8.5 and 10lbs. I like a 9lb bass. Get too far over 10 and it feels heavy, too far under 9 and it doesn't feel right on a strap. I have sold basses that weighed 10.5 lbs and 8lbs, both because the weight was uncomfortable.