Thank was my thinking as well. His site says they test it to make sure it's water resistant but... It shouldn't have arrived with a loose case back. Likely someone just got lazy.
Depends on how often I think I'll wear a watch. If it's an occasional wear, I don't mind the 21J. My current thinking is, if I really like this one and wear it often I'll sell it and upgrade to BK's model.
Or not.
That's the fun with reps.