You won't regret getting Aperture. I use a Jpeg workflow and it's wonderful. I am getting to the point with it now that I will start using the ability to copy settings from one photo to a set of photos to speed up my processing. I think in the next upgrade to A2, you'll see something easier when it comes to this process.
But for going through hundreds of photos and selecting the keepers, non-keepers and exceptional photos (of which we all have many of, right?), it's very fast once you learn the short cut keys.
Roger is right, the tutorials Apple has are great. Also, I would use the getting started book when you are ready to get a feel for all the commands. It's a good introduction and takes a couple of hours to do. Set aside the time and you'll be amazed at how this A2 can work.
I'm still using a Powerbook G4 so, on a MBP, it's going to be faster and better.
A word about iPhoto, it does some things A2 can't do. Like mix music with a slideshow or do a calender. This is where Apple was thinking. Why build that into A2 when every Mac comes with iLife. You just pull over the photos you want into iPhoto already processed and build your photo projects there. Works great.