I have just started checking out Photos for OS X. The absence of star ratings in Photos is definitely a pain. However, I find that rating photos via keywords is not as bad as I had originally expected. If 1 Star, 2 Star, 3 Star, 4 Star and 5 Star keywords are created, with the shortcut keys 1, 2, 3, 4, and 5, respectively, it is quick to add or change ratings when the Keyword Manager is open. Pressing a number key adds the rating. To change a rating, press the number key corresponding to the existing rating to remove it, then press the number key for the revised rating.
Five top LUMIX cameras are getting updates this month, including the full-frame LUMIX S1 and S1R, plus the micro four thirds GH5, GH5S and G9.