Blazing fast Safari 5 is much faster on My powerbook G4 1.67 running Leopard. I would say at least 50% faster but it seems even faster. As other ones suggest here I would try to reset safari but first try to remove add-ons first. I Myself didn't do anything,just installed it,restarted and it got way faster. And to My surprise a bug has been removed. I had issues with ebay,when I opened an item to view it I always had to double click on the back button in Safari 4,didn't have this issue before,now its gone,luckily. ( There is a thread of mine on forums here about this and more people had this issue).