I recently upgraded to a Marineland 150 gal cube (36x36x24). I love it! The 24 inch is the deepest I'd go with, as I do get my armpits wet when reaching towards the middle of the tank. But I absolutely love the proportions of this tank; it gives you such a sense of depth and space....
I am not crazy about Marineland's corner overflow, so if I had to do it again, I'd have a bean animal (my tank is visible on 3 sides). I think of it as a peninsula cube.
This is my tank journal:
http://www.canreef.com/vbulletin/sho...ht=water+floor