Apparently there’s quite an active discussion occurring on the Linux Kernel Mailing List, about the value of swap space. Here’s an assertion by Nick Piggin that I found particularly interesting.

Well it is a magical property of swap space, because extra RAM
doesn’t allow you to replace unused memory with often used memory.

The theory holds true no matter how much RAM you have. Swap can
improve performance. It can be trivially demonstrated.

Yes, swap can improve performance if memory size is held constant, but it can also be trivially demonstrated that swap won’t improve performance in some pretty obvious cases. Here’s John Bradford’s cogent reply.

Strictly speaking no, but instead of replacing unused memory with often used
memory, the often used memory has it’s own silicon, so the unused memory can
stay paged in as well.

Or to put it another way, however much swap a machine has, installing that
much extra physical RAM, and removing the swap space will almost never cause
a loss in performance.

It should be obvious which of these two I’d rather have working on a kernel I use.