theoretically it may affect your credit scores; however, in my experience, it does not make a big difference. I've canceled a couple of credit cards, when I apply a mortgage, I still got a good rate.
not bad. 8 ~5 s# D+ M% o! N/ M! f3 S4 c$ c- { s7 \3 y6 Z# t* H
but compared with other rewards cards, the rate of getting points is not good enough. But if you buy things a lot at their stores, it is very good.