Are you willing to share why you are moving to LR? I'd love to hear it. I've been thinking about a move to one or the other, but haven't committed yet.
I am by no means a pro, but do spend a lot of time and pride to my photos.
1. One of the biggest things for me is the end product of the photo. I took my top 100 rated photos from aperture and imported the originals into LR. I edited them to the best of my ability in each program then compared the two. I liked the end product in LR better for my test. I am sure I could make both look the same, but LR editing just made more sense to me. I had been using aperture for some time so should be pretty good with it.
2. I like editing in full screen, I never liked how with aperture the editing panel floats over the photo. I was always moving the stupid thing getting it to the right position. LR is right next to the photo.
3. I like how I can customize the look of LR. I have a smugmug account, and made LR have the same header with my name, and have the ability to hide it. It looks very professional.
4. I love the sharping in LR.
5. Selective editing. Easy way to save skies, or small mistakes without going to photoshop.
6. Comparing edited photos and originals side by side or half and half. Nice to see the progress.
These are just a few. I fell in love with LR. It is the first program that just makes sense to me. I never could figure out exactly make levels work how I wanted in aperture. I like how LR handles presets also. I enjoyed aperture but love LR. I will miss how OSX integrates with aperture though, with iphoto, my screen savers, ect.