Timely post!

I agree with you on the Contrail - the odd-shape stiff top threw me off, and I didn't see the point. Too bad, because I would really like to have a double-pole handle.

MLC and Load Warrior and a couple others got ruled out because of weight or pushing size limits.

I narrowed it down to the Shuttle (which really does look like a Porter on wheels, except I couldn't figure out the reduced capacity) and the Ozone.

I got the Ozone (with a lot of misgivings, but it's easy to return). I have to admit, the shape empty really threw me off - it just didn't look like it would hold it enough. However, it is sitting down the hall, almost fully packed for an upcoming two week trip to China. I haven't even put anything in the back compartment yet, nor is it stuffed (and I have a spare pair of running shoes and a Camelback pack and bladder - the Camelback padded straps/back take up an annoying large amount of room).

My go-to bags have been non-expandable rectangles with no outside pockets. I read a review about the Ozone where the reviewer said he just kept stuffing things into the bag and it kept swallowing it up. That seems to be my experience. I'm so used to a single big space that I couldn't really visualize all the compartments. The two outside pouches really hold a lot, and I really like the inside compression straps. It is definitely going to take some getting used to - using a 'suitcase' with 'backpacker' style organization.

Now that it is mostly packed, I have to admit that I'm actually pretty impressed with the quality. I got it as a carry-on, but I feel confident that it's tough enough to handle being checked from time to time. Osprey's been building good backpacks for a while, so I trust the fabric, zippers and overall construction.

I'm concerned about the single pole - I go over cobblestones, sometimes stairs, gravel -whatever, and I often have a second smaller bag on top. I'm concerned about the bag pivoting or the second bag rolling off. I noted, however, that Osprey has some smaller 'companion' packs that come designed to work with the single handle - they have a built-in large loop that slips over the handle instead of a sleeve. This means they ride farther down on the bag, not really sitting on top of it. I have a similar strap from another bag - I'll either use it to attach my personal item to the carry handle of the Ozone or just slide the hand loop on the personal item over the pole. I think there's still the potential for it to rotate around, but I already have that with my current two-pole bags if the second bag isn't carefully balanced.

I'll report back on my actual experiences when I get back. China's a good place for me to try it out - not the most demanding terrain, but I'll be on public transport, up and down stairs, rough roads, subway, etc.