Since we just touched March and I have already flown 60+K miles in 2016, I have a few well-tested thoughts on this subject:
If you are a heavy duty traveler, luggage is a tool. It needs to be practical, rugged, adaptable, low/no maintenance, weather resistant, a reasonable weight, and - ideally - good looking.
Look at any road warrior and, I can assure you, "leather" is not a material you will be seeing. Ever. It's an utter fail in most of the baseline requirements above.
You can debate all you want, but polycarb rollaboards by folks like Rimowa or Halliburton (among many others, but you sounded like you are looking at upper-end bags) are the way to go. Lighter than nylon, flexible enough to be massively overstuffed in a pinch, and tough enough to protect the odd bottle you may be toting back, they are hard to beat.
The bigger Q here is two-wheel or 4-wheel "spinner" model? The spinners are much easier to truck between gates, but you lose some interior space and have a larger outside dimension. May not seem like much on the showroom floor, but just wait until you are holding up the line trying to jam that spinning sucker into an undersized Euro overhead and you'll be thinking twice as you can feel the hateful stares burning through the back of your head. I went with a two-wheeled case, but would do 4 if I ever bought a 26" that would check. (Doubtful)
Which brings me to the next point: No bag checking. I think this guts the "thieves like Rimowa" postulate. Trust me, the travel industry is far more fragile than they'd like you to ever imagine - more so now that we have moved to the post consolidation "just in time" model that has no "plan B" if anything goes wrong - and to check a bag is to immediately introduce the risk of self-inflicted collateral damage.
I know Rimowa makes some hard cases with a nylon outer pocket setup but, again, you are now increasing your profile dimensions. Buyer beware.
My solution is to have my rollie and a very nice leather briefcase with an extra main compartment and an over-the-handle sleeve in the back to drop on the rollie so the profile is was small as possible. Then get two clear zip bags of equal size from someplace like the Container Store: one of toiletries and one for charging crap/cables/adapters. Trust me, they require equal volume. If I am domestic and going thru TSA, the bath stuff goes in the box and the electronics goes in the brief; If I am overseas, I just swap them. Problem solved. The bag in the brief goes next to the Bose headphones; the other compartment is for the laptop, iPad, notebook, papers, etc.
FWIW: Macbook goes into a nice custom leather sleeve that can be used as a standalone for meetings if I don't need the whole briefcase. Extra bit of padding and enough room to stuff a few papers or a PPT deck and it comes across like a folio rather than a "computer case."
Whatever you do, don't pay retail. i don't care about the brand, luggage is a commodity item where trends and colors come an go. I currently use a Halliburton ZeroRoller that has been utterly bombproof and has acquired a great patina from being banged about. Retail was $600+; I paid $190 with free shipping. With luggage, the internet closeout is your friend.
Finally, let me say that I am married to an amazing woman who utterly rejects all of the above out of hand. Two weeks ago I rolled in from a 9-day/5 city/4 country trip with the setup I described above. She had just come back from a 3-day weekend trip to SF that required a 26" hardcore, a 22" hard case (both checked), a small rollaboard and a handbag a 13/d bigger than my briefcase.Go figger...