I bought the MSD BTM unit. The problems I had with the crane unit seemed to be weak spark with only 6psi boost. I had to tighten the gap considerable. With the MSD I was able to open it up.
Another problem which I don't know I had with the crane until after I switched to the MSD was this. I run the tweecer with datalogging and I always noticed that the car would pull timing out at higher rpms. I couldn't tune it out and the timing didn't match what the spark tables said it should be. At the time I didn't associated this problem with the crane box. Then I upgraded to the MSD box and the timing problem was gone with ABSOLUTELY no other changes. To this day I don't know way that was happening but the proof was in the Datalogs, so I couldn't argue it. I still doesn't make sense to me fully why it was affecting the spark curve through the computer, but its enough for me to give the vote to MSD. Besides they are the top ignition company out there, hands down.
Good luck with what every you do!