I have an X32 and an S16 that I use regularly as the central part of my studio with X3. I have also done remote recordings using the venue's X32 with a laptop that has my old Sonar 8.5. Everything works well.
The X32's flexibility while recording is what makes me content with my decision. Depending on the required number of input tracks, I can have untouched inputs right off the preamps and processed inputs (via the P16 bus) both recorded. Headphone mixes can have effects (reverb, compression) generated within the X32 with no concern about the latency settings of SONAR.
Moreover, I have three sets of speakers that are controlled from the X32, so the monitor controller function that would be separately necessary on a conventional interface is fully integrated and flexible. I have an Audio-Technica condenser mic on the talkback channel. I only use the Mackie Control features for quickly getting rough levels on captures before drawing volume automation. In general I find that doing track volume automation with a mouse is fine with me once I've taken full advantage of the simultaneous changes and experimentation that's possible with a handful of 8 sliders to get the mix started in the right direction.
i would absolutely love to have the ability to toggle between track and bus fader control, but that doesn't work with the Mackie Control implementation in the X32. I would also love to have the same 32-fader bi-directional, plus scribble strip support that the Reaper OSC functions have enabled for the X32. Sigh, perhaps someday...