So I'm not 100% sure that my Ubuntu 10.10 has become slow because of Unity or some other reason, but yesterday I installed it using Ubuntu Software Centre.
I logged out and logged in using the Netbook Interface to see how it worked. My Ubuntu suddenly became very slow and unresponsive.
I logged out and logged in using the Desktop interface again, but it continued to be slow and unresponsive. I went back to Ubuntu Software Centre and uninstalled Unity, even tried rebooting my computer, but its still very slow.