Overflow options??

[eWarren]

Has anyone out here use this CPR C-Siphon overflow?

I brought a 150g tank last Christmas. Back then, I did not think I need a sump. So I didn't get them to make me overflow. Now, I really feel like I can use a sump. The only option seems to me is the CPR C-Siphon overflow. But I also hear a good number of people who use this product and had flood. Any suggestion at all?