Celcom seems to be improving a lot. They started pretty bad , but now they are on the right track. Currently , they do not block ports for p2ping , it makes bit torrenting possible on the go (which is a good thing) , but do not expect anything for gaming as its 3g and the latency would be high. Apart from that , Celcom is part of the telekom group of companies (that includes tmnet) and they share the cables and the whole connectivity part with TmNet , hence you'll get better speeds as opposed to maxis whereby they have a small international pipeline
I've found out something today , maxis is even trotting my world of warcraft. Beat that