Steelarts,
I have both an Ohana sopranino and a Bruko travel uke (the slim one). My two cents:
The Ohana sounds great and full, and as you would imagine a solid mahogany uke (albeit a higher pitch). You can play with different tunings (mine's tuned to D), which is fun, too. That said, I treat it like a solid-bodied uke. I'm not sure how well it would withstand travel. Plus -- I'm guessing this has to do with the scale -- it can be a bit of a bear to tune; it is very sensitive. I've also heard there can be intonation issues up the fretboard, although mine seems fine.
The Bruko is solid maple and has that distinct Bruko sound -- again, my guess is it's a result of the one-piece carved bridge and saddle. It's brighter than the Ohana, and a heck of a lot sturdier. It's still light, mind you, but it feels strong. There's fewer pieces in total, which to my mind means fewer opportunities for mishaps, and it's stained black, which allows for, well, less careful handling. I got mine used, so it had a couple of nicks on it. I added my first nick last night , and it just felt character-building. I would not have had the same reaction with the Ohana.
I also had/have a dolphin. I lent it to a student (a responsible one) and within twelve hours the neck was snapped from the body. They're great little instruments, especially for the price, but durable is not the first adjective that comes to mind. (Then again, if you don't sit on it then this point is moot.)
An earlier post, I think it was DNewton's, makes a valid point: You're not saving all that much space with a travel/short scale uke, so any durable soprano would work. Have you checked out the new plastic ukes through Kiwaya?
http://takumiukulele.com/noveltyukuleles.html
Cheers.