I've been using Aperture 3 for a long time and now have about 50K images. Just upgraded to a 5D Mark III and that combined with my 4 year old computer are really causing me a LOT of headaches with waiting for importing/indexing/etc. I'm going to be get a new computer in a few months and want to know from REAL users whether LR4 is actually faster than Aperture 3 for initial image importing/indexing/rating/etc. When I started with Aperture 2, I compared LR to it and Aperture was noticeably faster. I don't have the computer resources right now to load my entire library onto LR4 to get a real world preview of it and want to know from serious photographers, WHO HAVE REAL WORLD EXPERIENCE, which is faster for batch importing/initial rating/previewing. Aside from this I have no other problems with Aperture 3 so please don't recommend LR4 over aperture for other features.