lot's of debaters in the battle forum have been using the phrase "if that's only his MS imagine what he can do with his EMS". all I know that one stays for ever and the other doesn't, never heard of added abilities. I stpped watching naruto btw.
- Every other increase in the Sharingan's level has led to new skillsets and increased potency of previous skills. The assumption is that EMS does this over regular MS as well.
- I don't think they've shown specific EMS techniques but the idea is that you can spam attacks all day and not risk blindness, which sets in pretty quick if you use MS techniques a lot. Neither the manga or the anime really shows progress of time that well, but it seemed like Sasuke started going blind about a month after unlocking the MS.
- It's also been suggested that EMS is a step along the path of gaining the Rinnegan, so it has that going for it as well.