According to the CBS telecast, the green speeds of the Riviera greens were 12.5+. This seems excessively fast, especially considering the huge rolls which have been accentuated by sand build-up from sand thrown out of bunkers for years on many holes. These green speeds are at least one reason for the complaints about the unplayability of the greens by the players as discussed in other threads on here.
This illustrates one of my pet complaints in modern golf. Green speeds have become a macho thing at many clubs. People brag with pride about how incredibly fast their greens are--I've heard people proud of their greens being over 14. It's like they feel that super-fast greens make their course better--and them feel stronger and better. In my mind excessive green speeds are wrecking play at many old courses with greens originally built for speeds of 6-8. And it leads to boring golf, players playing excessively conservative and defensive, and taking away the excitement of skillful putting at many courses.
I don't have any set speed that I think fits all courses--it obviously depends on the rolls of the greens, the size of the greens, the type of grass, etc. But I do think that speeds much above 11 should be somewhat suspect--and may be there in many cases just so mainly male golfers can brag about the speed of their greens as a sign of their masculinity.