I was in the same position, around a month ago now. I was doing 12 units and was contemplating for a long time whether it was a good idea to drop EES, main reasons being that it has a lot of content, doesn't contemplate for this content in scaling, and the teacher was teaching the subject for the first time, although I did readily enjoy it. In the end I decided to drop it, haven't even considered a regression towards the issue and am really utilizing the extra free periods.
In my opinion, if the only reason for dropping that subject is because you don't enjoy it, it's probably not a strenuous enough reason for the commitment of dropping a subject. No one adores a subject, they might prefer it over others or sometime look forward to a certain lesson, but in the end; school is school. However, the ultimate decision is obviously yours, if there are other factors which have contributed to your consideration of dropping a specific subject, then go ahead.