I also have the Arkel Tailrider (since 2004), and it's a wonderful piece of luggage. DH has one too. It expands to hold an amazing number of items, the rain cover is very cool (though I rarely use it since I avoid riding in the rain). In six years of use, it has developed no defects at all, other than a slight fading of the the red color from riding in the sun. It's nice and bright and visible, though. We also have Arkel panniers, and they are wonderful as well. Just can't say enough about these quality products -- and the folks who work at Arkel couldn't be nicer or more helpful!
No affiliation, just a very satisfied customer.
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow