Well, i did it despite my prejudices. I had had bad experiences with upgrading an os before a got a mac this year. Both PC-BSD and Windows had let me down in their new os's, and ubuntu was the only os not to let me down. I thought, well, this is apple. Not Micro$oft or a group of sad nerds with no social life. OS X is the best os i've used, and they seem to have a habit of pleasing everyone. And it was only £30! So i removed my prejudices and bought it. And i upgraded. It took less than an hour which is all good. And now i'm running os x 10.6. And well... what can i say?? Nothing much has changed, apart from: 50% of my apps don't work anymore, iTunes is very slow and has a habit of duplicating my tracks, expose looks tackier, my volume, brightness and play/pause/next/back buttons on my keyboard now lag, It's forgotten all of my bluetooth devices, My airport signal strength isn't as good and the internet is very slow, The system preferences wants to "quit and reopen" whenever i click something, and Quicktime movie player has been replaced with something that resemble's a program i used when i had windows 3.1, except it has curved corners, cutting out bits of my movie. It does all of this, and only takes an extra 512mb of ram than the previous version, making my games rather jerky, meaning ill have to pay for a ram upgrade. Way to go apple... you've really impressed me! OS X Vista Leopard! I fully recommend! Anyone not wanting to upgrade, just do it! You won't regret it. Trust me.