well ... the only times I've ever really had swap going is when I've done something dumb and tried to use more memory than the system actually has, in which case the thing gets so swappy it basically seizes up anyway
yeah I didn't understand that either until I was talking to some linux person and he said it would just swap stuff out it thinks you're not using right now so it can use the RAM for caching instead
or something like that, I forget exactly what he said
it was basically "omg you turn swap off? u noob, now you will listen to why you're a noob" and I did the IRC equivalent of nodding and smiling at his explanation, while making no changes to my swap configuration
I guess one of the downsides is that if you run out of RAM the OS will terminate an application, or a malloc() will return NULL and since most software isn't coded to handle that, the memory hungry app will just crash immediately. so if you have unsaved work etc. you'll lose it, whereas with swap enabled at least it will be able to struggle on