How do you tell a real Submariner from a Grade 1 replica?

[jblaze]

I've recently purchased a Rolex Sub (non ceramic) and love it. I'm 99.9% sure it's real, as the seller has a lot of references. However, I came across these "Grade 1 Swiss replicas" which use ETA movements and even have the etched crown in the crystal (and the ROLEX ROLEX ROLEX on the inner bezel). I won't link to any of their sites, since I don't want to promote any of them.

I'm sure I'm paranoid, but is there a way (besides opening up the caseback) to tell one of these fakes from a real Rolex? I was comforted by the laser crown and ROLEX ROLEX ROLEX, but not I'm (slightly) concerned. Thanks!