Biggest difference, for me, has been the fact that SATA supports NCQ. Many people don't seem to notice the difference with NCQ, but I certainly do. Some tasks are many times faster with it.
Sustained transfer rates are not that different between SATA and PATA, all other things being equal.
...rightful liberty is unobstructed action according to our will within limits drawn around us by the equal rights of others. I do not add 'within the limits of the law,' because law is often but the tyrant's will, and always so when it violates the right of an individual. -- Thomas Jefferson