Custom tunes are much, much better than an off the shelf tuner. Plus, they are both comparable in price. Read some threads from people switching from a box tuner to a custom tune, that should be more than enough to convince you.
Im convinced just not enough for my truck to sit for days waiting..
i had my OBS tuned it person, but i think you should be able to do the same way as the NBS they mail you a tuned computer, and you mail your stocker in as a core.
If that is the case then that will work, I just cant have my truck sit for days waiting...