Not much gets posted in this forum, so I thought I'd remedy that...
I've had my Kriega R25 rucsac now for about 18 months and given it a lot of abuse. It's got wet, soaked through and my stuff inside has stayed dry. It always stays put even on the most spirited of rides, and is extremely comfortable. The zips, clips and harnesses are extremely tough and easy to operate - no flapping about.
If anyone is interested here is the website: http://www.kriega.com/
I've nothng to do with them just thought that if any of you are in the market for a new rucsac, you can't go wrong with one of these beauties. In my opinion