I'm better at being an admin, being in charged of what takes place. A mod is good to, but if a situation gets out of hand, all you can normally do is lock it, and not give an official warning to them.
Admin. You can be more professional as an Admin. I find Moderators get all of the problems on the forum. Such as little petty problems and help with the site. Admins, however, have way more respect and can act more professionally as they run the entire forum. I like to think of them as like the Governors of a city.
I think I'm better as an administrator because I like being able to make changes that the community wants and that won't affect the overall forum or community.
A decent Admin should be able to Mod just as well. I have been a Mod as well as now being Admin and I do both very well, IMVHO.
Mods get a lot of the petty issues but Admin do as well. Admin just have a lot more on their plate than Mods do with taking care of the entire forum and not just certain parts of it.