I have played PKR a good deal. I was one of the early beta testers.
If it doesn`t work for you, it is likely because you are trying to access it from an IP address in the USA (it is not open to Americans), or because your PC is not beefy enough (it needs a fairly high spec).
Graphically, it is the best there is. However, I must admit I seldom play there any more. Their tournament structures are much too fast for sensible play and, since I am largely a tournament player, no amount of prettiness compensates me for that rather significant defect.
ok I am an American and I play PKR a lot, just for fun since I cant deposit. That site is a riot when playing for fun, I cant get enough of it. Anywho, you can install the software even with an american IP address. You need a good graphics card, I have a powerful dual Nvidia card whic can support pretty much any game out there. So the IP address is not your problem. If you manage to get it working though, it's def worth the effort.