Lightroom is faster than Aperture, no contest. The difference in speed was greater before (in Lightroom's favour), but now Aperture is faster than before and will work on a MBP or something similar to it. You just had a bad user experience.
I like Aperture because I think it's great for organizing photos. That part is superior. I like Lightroom, and will like it more because version 1.0 will have versioning and master copies, much like Aperture. Organization will still favour Aperture somewhat, but Lightroom's editing power and ease of use means I rarely ever go into another program to edit. So Aperture is slightly better at cataloguing and organizing photos, while Lightroom's editing is far superior (and it's cataloguing is going to be better in 1 or 2 months when v1.0 is released.
Oh, Lightroom also runs faster on the same hardware.