If you could design your own travel bag, what would you pick? Or what would you like to change about your current model?
I'm trying to decide what is most important - price and weight vs. essential features and all other things about pack!
Thanks!

There is no right answer to this. Only you can decide what features are important to you. Everyone has their own preferences. As an example, lockable zippers are important to me. To others they might not be. I like a bag that has hidden backpack straps. Others don't care.

Beyond that, and even staying within the category of carry-on bag, one single bag wouldn't necessarily be optimal for any particular trip. I currently have EIGHT bags that fall into this category, three with wheels, five without, the choice to depend on the nature and length of the trip, which in turn impacts what sort of clothes one needs to take, whether the trip is strictly by car, perhaps by bus, if by airliner whether conventional size or downsized regional jet or even smaller, how one will get to one's lodging at the destination, and so on. Of course, ending up with that many was NOT an intentional plan. Beyond that, several were not very expensive even at list price, two or three were bought at deep discount sales, etc. Hmm...clearly I need to schedule MORE trips...