Hi
I snapped up an open-box HannsG HT231 23" 10-point for £110 to see if touch would work. Of course, CW might be enabling Sonar to be touch-compliant, but the interface needs to be designed ergonomically to fit the proportions of the human finger! That said, I have to agree with others as only a few things are implemented properly as of yet. Console buttons, knobs etc., VST & media drag 'n' drop from the media browser, ProChannel plugins and fx bins are still hard to use. I emailed tech support and suggested they had a look at Presonus new live audio software which is designed for touch screen. Track pinch and zoom seems to randomly zoom in/out too much sometimes, tapping on each new fader/button etc. requires a tap to focus on it before using. And yes, you still nee a keyboard and mouse.
Having said that, I've been having some fun with it. The matrix is great to use, and moving my hand and arm over the console is something like moving across a real desk, except you then touch glass and not a real control. If you're like me and spent decades operating analog desks, it's a nice 'retro' experience. I really love using the new virtual keyboard when auditioning samples and have started using it to input simple instrument lines in real time and edit midi with it by touch.
I keep my control bar at the bottom and my screen is lying at about 30 degrees from horizontal. I'm going to build a new desk and will integrate the screen in to the desk top. If I bought again, I'd get a 27".
All in all - touch on Sonar has a lot of potential and has some uses now, but I don't think it's a serious proposition yet. Good to play with though.
Hope this helps!
Best
Gary