micv
Most of my controller needs (and most time consuming to map) are for controlling VST synth and Fx.
The X-Touch Compact looks great and I think Sonar do support Mackie MCU, but it's too new to know how well it would actually works with Sonar or how reliable it will be long term.
Mackie can not control VST synth, only Strips/FX (it does not work throw ACT).
Have you checked that endless encoders is really what you want to control VSTs, especially live? One "tick" on endless encoder is normally physically longer then on normal knob. That means you either have less accuracy or should turn it more than on 270 degree for full range. If yes:
1) old Novation AutoMap style
2) new NI and AKAI solutions
3) almost any board or board plus controller combination with acceptable for you hardware quality/capability. To use with my plug-in. At the moment, only Nektar Panorama is known to be NOT supported (unknown proprietary protocol for which I was unable to find any information)
(1) and (2) are VST wrappers based. You get more pre-maped controls and do not need to deal with a bit broken at the moment ACT (quite complicated to make initial mapping, but once done it works well). There are known problems, at least with (1). (2) most probably is not going to cooperate with FX control.
(3) is not company supported solution, but most flexible. And the flexibility means it can take a while till you get the mapping you want (I and other will help). Check BCR-2000 threads and Preset section on my site (see signature) to get an idea.