Bought a multi-user pack and installed it on 2 MacBook Pros and one new 24-inch iMac; all current Mac models. Relatively quick installation on all the machines ranging from 1:30 hours on the laptops and 2:30 on the iMac.

Also bought a external hard disk designed for the Mac Mini 750GB made by Iomega. Timewrap worked perfectly first time.

I believe we were fortunate to have the latest hardware (as a recent result of the previous hard disk failure on a laptop and on the iMac causing us to get new kit) so the software installation was very straight forwards.

Understand problems are expected on older version of Macs.