1. Only the intake goes in the water, so it's not taking up valuable tank space
2. Outflow moves water on the surface around quite a bit
3. Easier to add any kind of media you want, provides a bit more flow
I wouldn't use either on a tank larger than 2.5/3 gallons, though.
I was thinking that the HOB was a better choice, but I just wanted to make sure because the Elite can filter 58 GPH whereas the Red Sea can only do 15 GPH. Luckily my local Petland sells the Deep Blue Professional version of the Red Sea nano, so I'll pick one up later. Thanks for your help.