Which is easier will depend on you. Some people give off lots of tells live and can't pick them up -- they are better probably playing online. Some people are more careless online and should stick to live play. There are many reasons for both. Depends on you!
i think it easier to play in a casino because you can read someones expressions however i have a horrible poker face so they can all see mine as well so that kinda bites i would rather play live though
To varying extents, I'd have to believe it depends on the individual. That said, since there are quite a few players who have successfully made the move from online to live, online experience does seem to transfer fairly well.