One thing about 4 wheelers, if you want to just do carry-on, is that they take up precious space which is counted in to the airlines' measurement allowance for your luggage.
So if space is important to you, make sure you look at the interior capacity of a piece of luggage as well as the exterior measurements.

Rimowa

Tuscanlifedit--We have those same bags and swear by them, lol! So durable!!! We have had ours for nearly 10 years and while we almost always travel carryon only, they have had to be checked a few times and and have survived just fine. DH used to have to use them to haul items for work, and for about 6 months the bags were flown and in checked baggage twice a week. Still hold up great. We have had such good luck with those, we bought another last year.

Oh... I already answered. This is an old thread :-)

It is an old thread but now own two lipault bags and love them. My husband took my 18 inch and I have a 20 inch now. I got a great deal on amazon for the 20 inch. They are so light but can put so much into my bags. They fit so nice into the overhead and loved it on trains. I got rid of the spinner and went back to the two wheels.