They sure look the same. Hmm MR. Aqua and GLA happen to have the same dimensions and they hit the market around the same time.
As far as ADA VS. MR. Aqua/GLA there is no comparison in quality. I personally think Mr. Aqua comes close to Do!aqua. I have not seen a GLA tank so I cant compare. If you have never owned a rimless tank or the tank will be a centerpeice in your home then I say go ADA. Mr. Aqua is a nice tank espicially for the price. I have 2xADA 30C but there gonna go on a rack so Im getting 4 Mr.Aqua Cubes. It does add up when you buy more that two.
I agree with you on the ADA thing. You can't really compare the others with perfect. I just can't talk myself into spending that much on a tank. Maybe I'd scoop on one of the smaller ones, but 500 bucks is a lotta bread for a 50 gallon tank. Reminds me of car paint, you really gotta look for the difference between a $1K paint job and a $5K paint job, and 95% of the people wouldn't see the difference.