Actually to be honest I've already stopped doing 5B->5C. When I was lurking around, I read that it was generally an unsafe string to do. And yeah, 5A->2B is something I've been using alot more lately.
It probably also doesn't help that I'm fighting against a Hell Tager, who has godly timing on all of his moves. It's hard to find any player that doesn't have a blue connection to practice with.