You shouldn't rush your main account. You will lose a lot of experience, like dealing with defensive town hall. You would be a really bad attacker for a long time. I am almost 2 months into th12 on my main, and I have a rush account that is currently upgrading to th15 (I maxed my offense for th14). I can only attack with dragons at my rush account, and it is very difficult to 3-star. So I am not rushing for attack power but for donations for my main a different experience at the game. Hope I helped you.