Nice stand! Yeah, 3/4" plywood on that size tank stand is mega-overkill; 1/2" ply would have been plenty, even without a frame, especially since you have it glued AND screwed together. Today's glues, if it's a quality glue and used correctly (with clamps), are actually stronger than the wood they hold together.
But even though your stand is overkill-solid, it has nothing on the homemade stand I just got with a 125 gallon aquarium (6' long) I bought. This stand had EIGHT 4x4 posts built into it and enough drywall screws and finishing nails to add a room onto a house! Luckily, since it was mostly screwed together, it came apart easily enough, so I'm reusing the 2x4 framing to rebuild the stand into something more furniture-like, since it will be a focal point of two rooms. I'm thinking about starting a journal here on my stand build and tank setup.