I played around with REW at first to take baseline readings before I treated my walls. Then I bought a SMS-1 and used the SMS-1 to deal with some peaks a valleys.

Although REW has a SMS-1 mode which will measure and compute the values to plug-in to the SMS-1, that was vastly different than what I was getting using the SMS-1's calibration program alone, so I stuck with that. It could have been a problem with my sound card or my SPL meter. Like Brian, I felt a little overwhelmed with all the variables and felt the SMS-1 was doing a good job without me second guessing it.

If I had been more patient, I probably would have gone for the REW/BFD solution. Ironically, REW is what made be want a SMS-1 right away after seeing what a difference a few bass traps made.