I have tried both. If budget is a factor then the Behringer FBQ2496 or BFD with REW software is the way to go. It will take a bit longer to organize yourself and learn the software but once you do you will have a program with display capabilities and higher resolution than the 1/3rd octave of SMS.
On the other hand, the SMS is easier to setup and use and its constant sweeps and real time display makes it easier to set up manual filters. The one thing I appreciated in the SMS was the flexibiltiy to move filters to whatever frequency needed adjustment whereas with the Behringers you are restricted to filters fixed at 20, 25, 32, 40, 50, 62, 80 100hz etc.
