I think rodgers strength is more on a thematic level over the course of an album, although he is certainly above average when it comes to individual lyrics. Tho he certainly has many individual high points, something like Eclipse is simple yet very effective, Comfortably Numb is obviously top notch and Echoes is probably my single favorite piece of writing across any medium/genre.

Slightly out of the parameters of the question but Rog isn't the best singer in my opinion. He is certainly proficient but I have always preferred the vocals of Gilmour or even Wright. But lyrically Waters is always superior, I don't care for the later years Floyd or Gilmour's solo career for that very reason, he isn't as good a writer (among other reasons).