Welcome to TRF Johnny!
Both the Sub and the Exp II are excellent choices. I've not heard of any "weak" crystals on the Sub, so I wouldn't pay any attention to that info; both are rugged dependable watches.
IMO, the Exp II would be the way to go; 2 time zones and more unique than the Sub. But, both are GREAT pieces. Be sure and show us some pics once you pick it up!