I want my tank up higher so I don’t have to bend down to look in it, and I am closer to a stump than tall. I build the stand higher with easy access to remove equipment if needed. The tank is 150g std. and I can almost reach the bottom with my arm. If I had to replace the tank I would use a 125g.
Another issue is with the 18” width. It does not leave a lot of room for rock work. Pretty much always ends up like a vertical wall.
I could make a 6” joke, about going to a 180g. However the 180 is not an option, although the same equipment would be used so no cost difference, other than new stand canopy, living room floor, paint the walls, touch up the ceiling, remodel a bathroom and whatever else it would take for domestic tranquility.
There is no perfect tank, I don’t care if I spent years designing it, and longer building. Once up and running I would find something that could have been done different.