I used them quite a bit for my Dart's parts and have also noticed for some items they are way cheaper than Summit/jegs or Autozone.

Most of the Dart parts I bought were a few years back when they had free super saver shipping and actually shipped stuff out quickly, like the same day or next day.. which meant if it was coming from WA, it could be 2-3 days which was very reasonable. But more recently I've noticed that they will "sit" on the free super saver orders before sending them out.. and of course, they allow the customer to go back in and pay to get it shipped.

Since last year I've signed up for the student version of Amazon prime, so it's free 2 day shipping, and some streaming video content too. Not bad.