Where would you shop & what would you look for?
I used a big rucksack before but back ache means switch to tow-on case. For a work journey on KLMI max bag size = 55 x 35 x 25cm (small!).
Wotta nightmare. Most the online specs seem to exclude wheels, but air lines include wheels in measurements, don't they? Is hard shell case more durable & more room inside, worth the extra £20-£40?
I only found this and this, not thrilled with either. Do I need to trawl real life shops with tape measurer in hand, What would you do?