there are definitely pros and cons to both, as a site mod you get a lot more thanks for what you do which definitely makes doing it less painful, but i really do like the overall feel of sandbox owner as looking after a whole community - especially one i've been a part of for so long.
the power gave me a massive bo nah seriously it's probably the higher capacity to help people, which extended when i became site mod. being able to help people out even with little things like getting you the "sammy" username back or making sure someone doesn't get punished where they shouldn't is fulfilling to me in some strange way.