I am thinking I should buy LR5, as I am not sure when Adobe will switch to on-line rental ONLY. So, in reviewing the updates, it looks quite useful http://www.lightroomqueen.com/2013/04/15/whats-new-in-lightroom-5-0-beta/ Has anyone gone from LR4 to LR5 on the same machine? How has performance been? Slower, faster, the same? This is assuming you've used both on the same machine. Specifically, I'm running Mac OS Mavericks, but I'd appreciate input from any OS user.