I've been doing weekly travel the last 2 years and a lot of regional jets last year. I never really check any bags so I'll give you my experience on carry-ons for Tumi and Rimowa.

I originally started out with the Tumi Alpha carry on but found it was pretty heavy and very commonly used by business travelers. This wouldn't be so bad but one time I almost mistook someone else's bag for mine.

I decided to get something a little bit more distinctive and got a Tumi Tegra-lite carry on which was great but the handle mechanism is not very well built. I managed to break 2 different bags on 2 different occasions. Basically the handle would not retract anymore. Fortunately, Tumi replaced both with brand new bags.

After the second one broke, I decided to try another luggage brand and ended up with a Rimowa Topas. Very distinctive and really my favorite so far. I've traveled with mine every week since August and it looks like new. I ended up getting a bigger Salsa Deluxe as my check in luggage and couldn't be happier. So if you're worried about dents, go for the polycarb Salsa deluxe line. Having had the Tumi tegra-lite, I can say I prefer the Salsa deluxe line better. Also, Rimowa doesn't seem to be as common as Tumi and other brands so you typically don't have to put any colorful straps or ribbons on your luggage to make it stand out.