Originally Posted by
no1mad
If cost wasn't a consideration, then the Arkel Tailrider would get the nod. And if you're commuting with this thing and need to remove it daily, then the Topeak MTX and matching rack would fit the bill.
That being said, try to find one that has a rain cover built-in (Arkel) or at least can purchase one that fits the bag (Topeak).
I love the look of the Arkel, but ultimately chose the Topeak because of the MTX attachment system. It was very handy to be able to slide the bag off when I got to work, and slide it back on when I left.