Thinking of getting one of these. I noticed most people get the more expensive stand alone systems or just the manual.
AVC-R or SBC - iD

 

I had the AVC-R and have installed and configured the HKS EVC-EZ

Closed loop boost control works great therefore the more expensive units are where its at.. But its expensive and isn't always easy for most people to set up.. The easiest boost controller is the MBC, and depending on the climate you live in, may need to periodically be adjusted. Many people try that first and many just stick with it.. Once their mods get more radical, and start swapping parts, they typically end going with something with boost control built in (Piggyback or Standalone.. UTEC, XEDE, AEM, AUTRONIC, take your pick) and even then, many end up sticking with the MBC unless they have a specific need to control boost (changes in altitude, or temp means closed loop boost control keeps a consistent level regardless of conditions) Others may want to have a specific boost curve (very fast spoolup without spiking, etc.. Requires more than just an MBC though its not always the case)