At lower levels, this problem was quickly resolved by a simple sleep spell. By the time sleep fell off in terms of usefulness, character development had left my evil side with a sort of begrudging respect for my allies. (though I still didn't care if they just so happened to be within splash damage range) By that point it was more of a mixed bag type of deal. The evil form was undeniably effective at nuking whatever threatened us, but couldn't be trusted to handle delicate negotiations. The good side would outright refuse to help in battle, but was a superb utility party member. Because of how the mechanics worked, being evil was only a temporary problem that would resolve itself as soon as I take a rest, which obviously I would need to do to get my health and spell slots back. So to answer your question: yes at first, but eventually no.