If you go to their website and click on "Tuning Services" they pretty much lay out the differences. The scan cable tune and the Autocal are different. With scan cable, you need to swap out the pcm after you log with the scan cable and email the file to them. They send you a tuned pcm to swap out and you send yours back to them for a core refund along with their scan cable. It sounds like a hassle to me but its way cheaper. I have the Autocal and it's so easy it's ridiculous. They have done 2 complete separate tunes for me and I can also swap between the original stock tune, an 87 octane and an 89 + octane tune in minutes. They can email your tunes to load onto the Autocal. With the scan cable, you can email the log file to them but have to wait for them to send you a tuned pcm, plus you have to do a crank relearn procedure due to the new pcm. Plus if I do any engine/ trans mods it's very easy to get a new tune and install it. Hope that helps answer your questions.
Edit: the Autocal can also show live data in real time in order to assist in troubleshooting, and BB will also let you log data if you're having trouble with your vehicle and you can send it to them to analyze. They offered to do that for me recently when I was having a random misfire/ stumbling but I figured it out. Like I said, they're real helpful.
