That's not what he meant
Jon has worked at many shops while RRE tuners have been there for years. The fact that Jon moved from one shop to another should in his view be a negative towards Jon, which in reality if anything just shows that Jon has been there and done that at quite a number of places. I personally suggest 5150, as my experience (and that of my friends' for that matter) has been nothing but positive.
I have a SST too and I am also wondering who tunes these trannies.
Did you not read the thread? Just go to Jon. As far as "tuning the tranny" goes, it's not yet possible since the TCU hasn't been cracked. Whatever SST tables are available through EcuFlash or Cobb AP (way more on EcuFlash) are rigorously adjusted by Jon or any other tuner who knows what they're doing. Only people I would trust with my car in terms of tuning are Jon Drenas, TJ Van Cott, Michael Golden, Rich and Tephra.