It took me a while to adjust to the multi dock in X1, after working in the pre X versions of 1 through 8.5 of SONAR. Initially I used the floating method with the track/arrange view on one and the dock on the other, then through X2 and X3 I got more used to it along with learning the wonders of D and Ctrl-D.
In X3 I tried an experiment and spread the whole window across both screens and it was very workable. Most views docked but floating certain views like the event list, the Melodyne window, when I needed it, and any plugins.
Then Like Grem I had the opportunity to upgrade my two 23" monitors to 27" this made everything much more readable. I still spread the main window across both screens making great use of the keyboard short cuts D, Ctrl-D and C, floating any windows I need just by grabbing the tab for the window and dragging it away out of the dock.
There are some things that could be added to some of the views like the note value buttons to the Staff view and the PRV but keyboard short cuts once learnt are also a way to work. Perhaps even a few teaks to the tool HUD relating to the active window but I can wait.