I've been using an Fstop Satori for a couple years, no complaints here. It's slightly taller than the Tilopa, but fits in the overhead. I've had it stuffed to the gills but never had any issue bringing it onto the plane.
Lots of pockets to keep small bits in and the ICU system is very clever. My model doesn't have a rain cover, so it will get damp in a downpour.