First - my main DAW is Sonar Platinum. I recently built a new PC and bought a 27" Planar touch screen. While I use it, I still rely on the mouse and keypad. I found I have finer control with the two instead of the touch screen.
A few months ago, my band needed a new FOH mixing system. I decided to go with an RM32AI (love it so much I am getting another), a CS18AI control surface, MOTU AVB switch, and use the new PC and Planar along with a few ipads. That control surface works really well with Studio One. When we record live, and mix back down with that combination, I have very nice tactile control - but the DAW tends to slow me down. The best thing to me is that, the VST's we use to record with - we use live because of the tight integration.
Net Net - while the presonus hardware choices do not work with Sonar, to answer the original post - if I had more money, I would
most definitely add a control surface for Sonar. What would be really nice is that the CS18AI could be ported to be used with Sonar and I could use Sonar to power the VST integration, live.
Take care
L