The fun part of their proposal is that you can set up RSC the way you want to. RSC was quite hard compared to RS2, so if you want to let your players enjoy the game with all its content, you could set the xp to 3 times as much, or something like that. With a few neat customizations, RSC could we played in a variety of ways to suit everyone's interests. Also, don't forget this is a solution to solve RWT and macroing. They had to come up with something that prevents this. So therefore it's a good solution. For free? What about the costs of hosting the server? ;) And often, those private servers are suffering from bugs.. probably from reverse engineering the code (that's my guess). With a Jagex hosted RSC server, you don't have bugs, and it saves you the hassle of hosting a server.