If you don't want to have lag in your blitz and bullet games then don't bother with Chess.com. It will frustrate you and cost you lots of losses in clear winning games. The worst part is that Chess.com doesn't even address the issue. The stuff they mention in their blogs about the issue is like giving a kid a packet of sweets and expect him not to ever cry again. Perhaps it's a cross-border thing with the US enjoying far greater bandwith speeds than the rest of the world. Chess.com won't mention anything down that path because that would have a direct negative effect on their numbers. My conclusion is that if your Chess.com connection is fine then you are ok, if not then don't expect it to get any better and not to mention all the times when their servers crash in the middle of your important local and national RATED events (not Chess.com's inaccurate rating system).