I have been using my new LaCie Poulton drive for over a week now and so far I am impressed with it. Running Leopard on it for my iMac means I now have a lot more free space over 700GB compared to the 15GB I seem to have with the original 250GB hard drive I had on the iMac.
So is it faster?
Yes!
It certainly appears to be faster, but I suspect that Leopard is also a factor as that made a difference with my MacBook Pro.
It was certainly a bit of a pain going through all my applications and re-installing them, re-activating some and finding the serial numbers of others.