I have the Bacch4Mac and continue to enjoy it immensely. It is the real deal, worth every bit of the investment to me. I rarely play anything where i feel it is affecting the presentation negatively. If so, just bypass it with one click, easy.
While I believe the Bacch technology is a game changer, the recently introduced Optimal Room Correction (ORC) module may be even more so. ORC has been in my system for a couple weeks now and I could never go back. I've used several products aimed at HT enthusiasts, such as Dirac Live, ARC, Audyssey, MiniDSP, etc. in my separate HT setup, but ORC is specifically targeted to 2 channel listening with the in-ear measurements and head tracking capability. It is very simple to use and adjustments with updated in room measurements are quick and easy to compare on the fly. Bacch and ORC used together are a very powerful combination that have really improved my listening experience.
In terms of pricing, the SP ADIO box is about the same as the DAC, preamp, Mac Mini and software, with various cabling I have now. It also has a 6 channel DAC and 3-way crossover, if you need it, among other optional modules. The benefit here is simply better integration if that's what you choose to do.
This is one of those products you just can't listen to on paper or from your keyboard. You really have to experience it first hand. I would encourage anyone who is attending Axpona to give it a listen for yourself. The only way to do that properly is to go through the ~2 minute sweep/calibration process for each unique listener. Wandering in and out of the room is unfortunately not useful in this case. They do also offer a 14 day in home trial for those with serious interest.