Well if it helps sway you, think of this: leaving is a one-way street, there is no coming back (not on anytime soon at least, and not on anywhere near the terms we enjoy now)... so choose to leave, and we cannot change our mind. Whereas choose to stay, and we have the luxury of changing our mind in the future if the EU fails to reform.
see you basically hit on the head the only thing im taking from both sides, better the devil you know.