I have the Topeak tourguide bag (5L) and the small Arkel bag (7.5L). The Arkel is a much nicer bag but consideralbly pricier- $60 compared to $170. The Topeak is very adequate and I was fine with it but I wanted to upgrade to a larger and nicer bag. Another bag that I considered was the Lone peak alta -$110- which looks to be the same size as the Arkel. I ended up going with the Arkel because it uses aluminum attachment brackets which are supposedly superior. I am sure I would have been just as happy with the lone peak for $60 less.