| That's the standard overflow used in All-Glass Aquariums (AGA) and Oceanic. (Both are owned by the same parent, but Oceanic are slightly more premium or were at one time at least.) Those probably the most common standard glass tanks with overflows sold here. But I haven't heard much pro or con on them.
I do not have my tank filled yet. I only bought it because I got a really good deal. I will not be filling it for a few months yet. The wait really is killing me, but I feel more prepared every week. I keep learning things that make me glad I didn't start already and do something that might not be best for the goals I have for my tank.
Checked the holes... there are 23 and they are just shy of 1/8" and actually over 7/8" long... so that comes to 2.5... Even if that is slightly high the top holes provide more than twice the area of the return line. So I guess I am pretty confident in it. If anything I coudl just drill a few extra holes in the sides or even anywhere lower really. | 
