I currently have the old chipset with my ZX, from what I have gathered, with the new Z4 chip, you can assign a separate MIDI channel to each pad on the Z4 that cannot be done with the Z3. What does that mean, well, you can hook up multiple modules, to include a piano with a MIDI connection and assign various sounds from different modules to any pad on the Z4. Anyone with the Z4 please correct me if I am wrong, but you could play strings with one pad, drums with others, horns with a different pad, all without having to change your program number on the ZX. You cannot do this with the Z3 chipset, the MIDI channel is global for that program, channel 10 (drum channel) is channel 10, I cannot put channel 1 and 10 on the same program, but the Z4 will allow you to do that.
As for the MacBook, I have purchased the SD2 software and I use GarageBand with the MacBook to run it as a VST. GarageBand has tons of sounds in it that are pretty good, and can all be accessed and played with the Zendrum. My setup is simple:
MacBook Pro (Using GarageBand and Superior Drummer 2.0)
UNO MID to USB cable
1/8" Y stereo splitter that splits the left and right channels to a 1/4" out
Two 15' 1/4" guitar cables (one for the left and right)
300 watt keyboard amp (unless I run straight to the PA and use monitors to hear myself
That is all I have used since March of 2010. You can buy different drum kits for the software and there is a mixer that comes with the program that gives you full control of sound, tone, gates, compression, basically whatever you could do in the studio, you can do with the software. I have only had to tweak two channels, my HH and Overhead mics, other than that, my sounds are right out of the box.
I would think that you could mix match software (it will take up some memory on your computer though) by running a host program like GarageBand, Ableton, Pro Tools, just to name a few, and load BFD into the program as a VST, then SD2, but my question would be why? I know some guys that have both but only run one or the other, they both do the same thing, it is just a matter of personal preference. I have listed to BFD (I know some of the guys that have it) and in my opinion compared to SD2, I like SD2 better, but that is just me. I am not a sound engineer and I feel that there is so much you need to do in BFD to get a great sounding kit, although possible, I just don’t have the time to sit and go through it, where SD2 for me was easy and sounded great right out of the box. The mixes were already set and it was literally plug and play. “The Mayor” Tom Roady would be one to ask about the tabla and dhol. I believe that the Latin Percussion add-on for SD2 has all of those. I also think there is an add-on for GarageBand called World Music that also has those drums available to use. Check out Tom Roady’s CD One Tribe available on Amazon.com, that CD was done using only the Zendrum, and there is a lot of world percussion on there.
Sorry for the long post, hope it helped out, feel free to email me directly at email@example.com
if you have more specific question, I will be happy to help.