I have this combination. I like it so far. I'm not really a "mixer" person but I am resolute in learning how to use this thing in depth!
Anyways, as far as controlling Logic, I got it working pretty easily. It seems that the faders don't seem as "sensitive" as my Logic Control (I think I mean resolution, perhaps?). I also have not played with the Tascam enough to know what other features are mapped out besides just level faders. It is very easy to switch between a fader layer and the Mackie control layer: just one button press. One thing though is if I have logic set to auto-sync in, and play, it will receive some timecode from somewhere and then stop after 2 bars. Don't know why this is, and it means I'll have to disable the Tascam's midi if I want to sync Logic to, say, Protools.
I connect my old 828 via Adat to Tascam and it sounds so much better than the Analog ins to the Tascam, so I'm happy about that. I have also the 8 Analog input card so I have a total of 24 Analog Ins which is nice too.
If you have any specific questions, I'll try to asnwer them, but so far, i like the combination a lot. My one complaint - they put the Control Room volume way up at the top of the mixer. My keyboard (Roland XV88) protrudes a bit from the front of the mixer, so i can see myself getting back spasms if I reach that volume control a lot!! I guess I'm shorter than the average user! Anyways, the mixer sounds good enogh to my ears.
Cheers
Ken
PS The manuals for the mixer are at Tascam's website. You can also take a peek at them to get a sense how things are setup.