Great question, looking forward to hearing the responses.
Having done some improvisation on the sax, it almost seems harder on the guitar--6 times as many choices
You might want to check out this fellow Stitch on YouTube. This video in particular I watched this morning and found it made a lot of sense to me. He talks a lot about intervals, and the function of each note in the pentatonic minor scale in terms of how they are used for tension and release.