There is another consideration on Macs. I have been using Aperture for a couple of years, and am switching to LR 4. All of the previous postings on this thread I pretty much agree with. The Aperture user interface is really nice, but LR 4 has better tools. I also use the Nik software, and it runs great on both Aperture and LR 4.
The problem with Aperture is that I'm running Snow Leopard, and do not want to "upgrade" to Lion or Mountain Lion. Apple, in it's infinite wisdom, is only updating Aperture that runs on Lion or Mountain Lion. In other words, Apple is no longer supporting Aperture on Snow Leopard, even though (as of this date), I believe something like 50-60% of Macs still run Snow Leopard. And another way to put it - to get the latest updates and/or upgrades to Aperture, you may have to install a new operating system. And this is likely to continue in the future, as Apple just doesn't give a hoot about "old operating systems". Installing any new operating system is fraught with peril, like breaking other non-Apple applications.
Yes, I'm delaying the inevitable, and will eventually have to update my operating system to the latest and greatest. But at least Adobe and LR 4 don't blow off 50-60% of Mac users still on Snow Leopard.
Because of this, I'm switching to LR 4. Apple just seems behind in the game. Aperture 4 should have been out by now, and Apple doesn't acknowledge that it's even working on Aperture 4. Kind of hard to stay with Aperture, when all indications point to Apple just dropping it entirely, and focusing on all the other gadgets they make.
Another consideration - LR 4 runs on a PC too, so if Apple drops Aperture or even Macs entirely, you can probably just move the data over to a PC, including all the adjustments, metadata, etc, etc with essentially zero hassles. Aperture data is locked to a Mac, and there is no way to move all the images you've worked on, with adjustments, over to another platform.
By the way, from what I understand, all Macs make great Windows PC machines too, not that I ever want to go back to Windows...
Last edited by leadfoot; 09-08-2012 at 10:45 AM.