If you have hair, or if anyone in your family has hair, do not use a foot activated pop-up in your bathtub.
I installed one in my new tub and at least once a month I had to disassemble the unit to clear the slimy mass of hair from the cross bars under the pop-up. I have 2 teenage girls and a wife with average length hair. I don't use that tub too often so I wouldn't know about it until they'd tell me how much they hate the new tub 'cuz it's backing up *again*.
After the third time disassembling it (tools required) I decided I didn't want to be a slave to my drain any longer and I replaced it with a lever operated pop-up with a screen on top. Now the girls clear the hair themselves giving me more time to fix the *other* things that they complain about.