So by usable, you do not mean literally just usable.
You mean actual, repeated, maybe even professional use?
Well, in that case I wouldn't recommend a rep. Heck, not even for normal time keeping, if it has to be reliable...
If I need actual reliability, I'd always invest $500 - $1000 in a legit product.
Reps are toys. Period.
Yes, usable as in you use it to time things, not just press the buttons when you first get it and then never again because it'll most likely break down if you do, or not keep good time.
I agree 100%, reps are mockups of actual watches that we buy for our own reasons. Some because we love the watch for its history or design but can't afford that one, others because they want to make it appear to others that they are wealthy even though they are not.. But for actual timekeeping, maybe that's not the best reason to get one lol