My tank is a 120g 12mm starphire glass and it works well.. Obviously its not 100% bulletproof and it has flaws but in my opinion its much better than any magnet with a pad on the back of it...
The one flaw is the fact that it doesn't float and my tank is 2" deep and the stand is very high, edge is at about 6'1- 6'2, so its a bitch to remove the screen and reach to the bottom...
But yea to answer your question, the long version will work very well and i haven't had the meet of a strong magnet yet so I don't regret buying it...
All my other magnets make perfect egg crate stands though with a little glue
