For 11 trips to Europe (24 weeks) plus many shorter domestic trips, I've sequentially used three bags since 2000. Non has had wheels, and none has ever been checked. I like to fly Lufthansa, and their weight limit is 8 kg (17.6 #), so empty weight is an issue for me. Because I don't over-pack my bag, and without the rigid wheel/handle structure, the actual length is unimportant. It easily squishes to fit in a 55 cm sizer.
My first carry-on bag was an RS convertible, right at the size limit and about 2½ #. As I learned to travel lighter, the RS bag became too large for the contents and, only partially filled, sagged a little. So I went to the OPEC bag, which was a little smaller than regulation and only 1¾ #. As I made more trips, I learned to carry even less, and eventually, the OPEC bag was too big. I finally got an eTech 2.0 Weekender Jr., which, sadly, isn't made anymore. It weighs a little more, 2½ #, but it has cinch straps to tighten the load, so I no longer have to fight a floppy, "too big" bag. (I thought of using the OPEC bag and filling the extra space with bubble-wrap, but I wasn't sure how security would take that!)
Before getting the Weekender Jr., I took everything that I took on one trip and put it in a box with known length and width and measured the depth. The total volume was about 1400 in³ (content weight was just under 10 #). That's about the volume of an Appenzell bag, which I have, and I thought of using it for my trips to Europe, but I don't like the way it opens (at the top instead of like a book).
One comment: I've never had a "carried-on" bag damaged, but then the fact that I handle it myself means that I can control how it is handled,and avoid damage.