The design and construction of this bag have already been raved about elsewhere, so I'll avoid that topic, even though it bears mention that is IS designed fantastically.
Foremost, the mounting system is fantastic. I love the metal clips and the frame loops. The bag is super secure, while still being easy to remove and install. Adjusting the straps every time can get a little tedious, but is HARDLY a real problem.
As far as space, it's nicely large, and having flexible sides, it suits anything I could put in a stuff sack just fine.
Another important feature to me is for it to be unobtrusive when not in use, which it certainly is. I ride a classic styled bike (Triumph Scrambler) and I can't help but think the look of luggage on it is more than a little awkward, to say the least. Despite looking very new compared to the rest of the bike, it's design is classy enough and very utilitarian, which suits me quite nicely. More aesthetically sensitive folks might disagree, but I'm very happy with the look.
The flexibility of the mounting surprised me. For something I considered a very simple piece of luggage (any given tail pack, not just this one,) I have found it AMAZINGLY difficult to find one that mounts in a way I consider sensible and unobtrusive. This one is perfect. It seemed over-complex at first, but after installing it, I appreciate the four little number of nylon loops being all that shows when uninstalled.
I didn't realize this was what I was looking for when hunting down luggage, but I'm sure glad I got it! It seems to fit the bill quite nicely. (Posted on 5/27/13)
This is a great bag which easily attaches and detaches from the passenger pillion of my Ninja 1000. The shoulder strap is a useful addition and makes it easy to handle the bag off the bike. My only complaint is that it would be nice to have an easily accessible pocket on the outside to store small items (sun glasses, change, etc). We drove through a lot of rain on our most recent trip and all my stuff stayed nice and dry. (Posted on 7/24/12)
I have several "dry bags" from canoe camping where you don't want your stuff to get wet if it comes to that. Heavy material and totally DRY.
I thought theses bags were way to elaborate and I almost returned them without a second look. I'm glad I didn't - there are so many features I'm not even going to try.
The BEST - the waterproof liner is white in color so you can see what is inside. One company that makes dry bags calls it the "black hole" - for good reason. You have to empty the contents to find anything.
So - excellent design and construction - lots of great features. You can strap these down in almost any direction with almost any combination of rack frame anchor sites.