Not all J-Points are set up like that. I have 2, one with a 4 and one with an 8MOA dot. The 8 is a bit faster, the 4 is a bit more precise.
I was a sort-of early adopter of the RDS concept on pistols. I've had a J-Point on a Glock 26 (milled by L&M Precision) since 2011. Sure it's more fragile...