I use a rear seat bag as you do. I have found that the Kreiga system fits my needs real well and it's tough and waterproof. I have the US30 as the main bag and 2 US10's that can be "piggybacked" to it. The Kreiga comes with a multitude of straps for attachment to darn near any MC. I don't very often recommend products, but this is one that I'm totally on board with. Oh yeah, with this set up I can carry almost 2 weeks worth of "needs" in the Kreiga alone leaving the saddlebags for those things that stay with the bike at motels.