i got the 2 dvd version of the WIS, they are well worth it, i bit fiddly to install, lots of instructions to follow, but once up they are great.
As mentioned, you need to play about for ages to realise the potential in them as they are a nightmare to navigate around - but a myriad of useful information.
If anyone here has the epc upto 2004, whats that like, can i buy a "backup"