Handbrake: iPad vs AppleTV vs AppleTV 2 vs AppleTV 3 presettings

[rrk100]

I have an AppleTV, an iPad 2, and the new iPad ("4") with Retina Display.

Using Handbrake, I have been creating 4 different versions of the DVD movie I am ripping via the presets:

iPad
AppleTV
AppleTV 2
AppleTV 3

Is there any advantage to having all 4 versions of a movie? Or do you think I should stop creating every AppleTV version? Since I have the original AppleTV, will I run into any backwards compatibility issues if I discontinue ripping from one of the AppleTV presets mentioned above?

I figure that the iPad version at least saves me some space on my iPads...

Thank you in advance.