I know you love that Travelpro, but do you realize that even the 25" Maxlite weighs something in the range of 7.5 pounds before you put a thing in it? In all my years of traveling, starting in 1977, I have never traveled with a bag that big or that heavy. I can't imagine needing it. It's way too big in all dimensions to be a carry-on. And I definitely can't imagine lifting a full bag like that up any stairs or into and out of a train.
My personal experience is that the bigger the bag is, the more I fill it up with "just in case" stuff instead of limiting to only what I really need. As a result, I've gone from a 22" (21.6x14.9x9.4 exterior dimensions, 2150 cubic inch, about 6 pound) spinner, to a 22" (22x14x9 exterior dimensions, 2500 cubic inches unexpanded, about 5.5 pound) 2-wheeler (amazing how much room those extra spinner wheels use up), to a 20.5" (20.5x12.5x8.5 exterior dimensions, 2050 cubic inches, about 1.5 pound) back pack.
I haven't used the little backpack yet. That's coming up for a domestic flight soon. When I just did those calculations, I was surprised to learn how close in capacity the spinner is to the backpack. And I must admit that I expanded the 2-wheeler to accommodate purchases and checked it on the way home. I did that because I could, but I usually don't have the option of checking a bag either direction.
I pack for a week and travel for 4-8 weeks. I agree with the statement that you and your friend should have a contest to see who can pack the lightest. I'm still working on that myself.
Update: Ahhh, now I get it. I'm not a shopper, except for jewelry. I'm at an age and a time in my life where I need to get rid of stuff, not bring more into the house. And with 5 kids, 4 spouses of kids and 14 grand-kids, I could never bring home something for everyone. What I expanded my 2-wheeler for was the playbill from the Globe, a calendar featuring a house I visited in the Cotswolds, a couple of refrigerator magnets and 2 T-shirts. Along the way I threw away an old swimsuit after I used it in Bath and gave 2 blouses that didn't work out to charity stores. I was so close to unexpanded capacity, even doing that and using my compression packing cubes, that the seemingly little bit extra put me over the line.