Sorry to jump in on an old thread.
I agree with most here and would go with AO.
My opinion is solely based on my (bad) experience. We used Soda on a project here 2 years ago and it turned out to be one of my worst nightmares since I opened my doors. I've always used AO and Plastic media prior to this particular project but decided to try something different. (For the record I usually try something "different" on my own personal cars before applying to a customer car).
Long story short, like others mentioned neutralizing after a Soda blast is a critical step prior to body prep, mud and paint. We thought we did a thorough job. The car was painted in June and by Sept we had a small pin sized bubble turn into a quarter sized bubble. The area was where we grafted a spoiler to a decklid etc. That area recieved several welds and grinding etc. After the bubble we chemically stripped the deck lid and started over. Again neutralizing the area before working with it again. This time we used panel bond adhesive and ground it down etc etc. Well.... 3 months later it reappeared. After the third time it was apparent the soda imbedded in a bad weld and festered. So after re-doing the lid 3 times, I rebuilt the decklid from scratch.
I could never charge for this mishap so I ate alot of time and material cost all because I chose to experiment on a clients car. I was just lucky my client was a great guy and understanding.