That is really nice! I walk past a 75 gallon tank every day at work, and it is one of my favorite sized tanks. Not too big, but a great footprint for a reef tank. It's basically the same as my 40 Breeder but a foot longer. Very, very cool. I bet you are really getting impatient to add things to it now huh?
Mine is now starting in on the cycling process. I just dosed some pure ammonia (3ppm) last night and because I'm using all dry rock in mine I added Seachem's Stability to kick start the biofilter. I do want to add a bit of live rock to my sump soon though too. So I'm just a bit behind you.
Noticed your circulation pumps. The right one looks to be towards the back and the left one looks more towards the front. That should produce a very good gyre effect, keeping the flow going in a circular motion around your rockwork (which is already nice and open).
Also noticed you have a heater in the display tank. I have three heaters in my sump (one in each chamber) but none in my display tank. The temps are at 78 degrees in both my sump and my display tank. I'm thinking you could just keep the heater in your sump so you don't have to see it in the display. Just a thought.