Hey thanks for the advice. I'm going to check out the Rimowa Topas.
As far as TSA is concerned, for flights originating in the US, I will use only TSA locks. However, for flights outside the US, I will add my own lock that is better than a TSA lock.
26" is more or less an ideal size for me, however, if the larger Rimowas have a place for your own lock, I'd be willing to go for a larger size on that basis.
I have one other concern about the latch-locking bags, wonder if the latch mechanism is more susceptible to breaking than the zipper-based locks. Hmm? Food for thought.