There's 3 different grades of glass, 1, 2 and 3 that are used in making aquariums that I know of. Oceanic uses the thinnest, strongest I believe grade 1. Ocean View uses grade 2, and a local aquarium manufacturer Domino Supply used grade 3 which is the "softest" and thickest and thus heaviest. My 225 was from domino and it was heavy as hell.
I don't know if the difference in glass grade would make a difference since it is siliconed/glued on. I'll just have to measure and ask them what the tolerances are.