Hi Dominique.
First, let's explain why I bothered making a slightly complex system with 3 tracks per instruments. We all know the main issue of VST Expression : once it is put on a track, nothing else that notes can be send manually (I think in cubase 6 you can send 1 CC, but it's not enough). And creating a VST Expression map is such a pain... that we all end up using vsl presets only.
One solution is to create two instrument tracks, one with VST Expression (the main one) and one without (for custom stuffs). But it can quickly become messy.
My idea is to use this really good method a bit differently : my main instrument track (where i put my midi notes) stays free from VST Expression (I don't know if this sentence is correct, but anyway... :p), while my other tracks, which do not contain any notes, have special maps i did, allowing me to choose patches just like keyswitches.
I know, you're going to tell me "well, if you had to design your own vst expression maps... No thanks"
Yes and No. Yes, I had to create my own expression maps, but they're way easiest to create and understand than normal maps. Because I don't use them the same way.
Currently, I have 2 KeySwitches track. One is called "matrices", and the other "Cells". So the first one allow me to choose my matrix, and the second one, to navigate in the matrix i chose. I Think screenshots would be much more precise than myself, so i'll post some as soon as I can.
So, my system has several advantages :
-midi notes and KS are not mixed.
-You can send CCs, and Keyswitches on the keyboard still work (can be handy when you're not recording)
-More flexible than normal VST Expression. (adding a new matrix can be done without touching the VST map if it's correctly prepared)
-Less messy than KS. You always see what's going on, and it's not possible to have useless informations all around.
-Setting up is easier than with normal vst expression. And can easily be shared.
But it also has drawbacks :
-3 Tracks for one instrument
-Slightly Tricky way to edit (and one very silly cubase bug to avoid)
-not as handy as normal VST Expression maps : you still have to know how your matrices are organized
-Notes and KS being separated, copying and pasting is sometimes easier, sometimes trickier, depending on how you organized your whole library. basically, if your keyswitches mapping is identical, normal keyswitches would be faster (copying and pasting everything at the same time), and if they're not, my system will automatically map them.
-Even though setting up is easy, it has to be done.