Senioritas are a nice airplane. I had a Seniorita without ailerons and it flew well. A friend of mine gave me a damaged wing from a Seniorita that he had. With the help of the LHS, I put ailerons on it and flew it. I never flew airplane with the wing without the ailerons on it again. The ailerons made a world of difference, even with the dihedral.
A funny thing about the wing we put the ailerons on, when we stripped the old covering off of the wing, we noticed several pieces of lead screwed on one side of the wing. We didn't think a whole lot about it, and the hobby shop owner counted ribs to cut for the ailerons. We cut both ailerons the same size, and when we tried to fit them on, one of them wouldn't fit. Upon further review, one side of the wings had one more rib than the other. (Come to think about it, I should have named it Adam and Eve). That was the reason for the lead weight. And it still flew very well.
Like the gentleman above me said, "Do what makes you comfortable", but the ailerons sure help. Good luck!