Well ... The Cobalt servers are very easy to use, they require no technical
expertise. They are also more secure then the regular linux boxes
but they are more expensive and are not upgradeable ...
About the gaming ... I don't know. You can try and then tell us!?
Cobalt servers are great for web hosting, and they have come done in price a lot, you can get them for a couple hundred dollars. You can update/upload programs to them if you know how. What are you looking to use them for?