Disclaimer: I don't have a tune from BBP myself, but I'm seriously looked into one. Now that being said, their PCM tune involves you telling them the details and mods to your truck, and then they custom burn you a tune. It's good tune, and a lot of guys say it really wakes up their truck. Now the Scan Cable Tune involves you renting the cable from them and driving around with it for a week or two. Then BBP uses the data collected to build a tune custom tailored to your truck. IMO it's a much better and much more accurate way of tuning the vehicle because it's made for your exact truck and if I wasn't looking into EFI at the moment it's the Tune I was going to go with. For more info on this visit the FAQ page on BBP's website or contact them via email. I'm sure they would be able to answer your questions a lot better than I can.