Magblade is super strong right now and magsorc is super weak. This is from a pvp perspective-- I don't pretend to know anything about PvE.
If you're newish to pvp both are perhaps good choices and you'll find them unique and fun. You may even have success against people of your own skill level. If you just want to know what's best... Go magblade.
I really feel like both take a lot to play well. MSorc ceiling is very low rigt now. Probably the lowest for most. MNB ceiling is the highest with how many tools you can use, you have to learn how to line them up