No comments on the rack at this moment. However, I have a Dave Smith Pro-2 which works very well with modular. Kinda was built that way. Have you considered looking at the Pro-2 with a 0-Coast? Or Pro-2 with a Mother-32? Also, Erica Synths (one of my favorites) has some great system options including DIY. I love the Mutable Instruments stuff. MATHS just kinda needs to be there. I recently turned a corner with MATHS and it has become so much more useful to me. It's a lot to absorb and I have a small head :-)