Thanks for this, I have been researching this recently and I thought I was going mad.

I was very keen on the Travelpro one until I noticed that it is only 22" x 14" x 9" if you don't count the wheels and the handles. I'm pretty sure most airlines count the wheels and the handles as part of the bag size. I'm sure you'd be fine to carry most of these on most of the time. But if I'm spending several hundred bucks on a piece of carry-on luggage, it's because I plan to travel with only carry-on luggage, and I want to be 100% sure I'll be allowed to carry it on!

I have also noticed most of these bags are stupidly heavy. The Briggs & Riley one looks like a good design, but it weighs 10 pounds / 4.5 kg, which is almost half your carry on max weight on the more generous airlines. The Tumi one weighs 6.5 kg, meaning if you're on a budget airline you can bring it on, but only if it's empty.

I can report that I have found one other roller garment bag which appears to fit the size requirements: the Delsey Wagram 2-Wheel Garment Carry Case. It is 55cm x 35cm x 22 cm and weighs 3 kg. The design looks okay, not as good as the Briggs & Riley. It lacks an external laptop pocket, but on the upside it looks like the main compartment is huge. I think it might be hard to find though. There are a bunch of Australian retailers selling it for AUD 489 (USD 300) but oddly it doesn't feature on Delsey's own website, suggesting it might be old stock.