I had this problem myself at some point. It has became slower over the time until the point (some 2 weeks ago) it was a pain to even type a text like this. I've reinstalled and suddenly it has became responsive again. I don't know what is the reason, but yes, when it's too slow / unresponsive, then reinstall is the good option. I don't know if it's such a known issue though, I didn't see too many people complaining (but I'm not that active either).