Ben and Ilya have noticed some anabolic effects thanks to the paleodiet.

Personally, the only type of paleodiet I experimented with ( to this day: 2 months "strict" and 11 or 12 months paleo plus cheese) is quite low carb:

-Only vegetables are cucumber, lettuce, celery, chicory, "fenouil" (can't find it in the dictionnary!), some lemon juice, and little broccoli and spinach. 
-All meats and animal products (brains, tripes, heart, liver, blood...and fat of course!)
-Eggs
-liberal amounts of olive oil (I also used other oils until they were discarded on the list some 10-15 days ago)
-Few nuts, seeds and fruits (a special treat: never more than once a week)

Therefore, I can't speak of the anabolic effects of higher carb paleodiets, which ought to be higher, I guess.

What I have found is that this low carb paleodiet holds pretty well when going down in weight: you either keep all your muscle mass or lose little of it even if reducing sharply: 
I went from the 100 kg (220 lbs) to the 75 kg (165 lbs) class this year with an increase in my competition deadlift from 400 lbs to 402.5 lbs and from 215 lbs to 230 lbs in my bench press.

IN MY EXPERIENCE, this paleodiet has been the best (and more enjoyable!!) of all REDUCING diets as far as anabolism and energy levels are concerned.

BUT, if you consider anabolism solely, it's far inferior to a "traditional" "bulking up" diet: same diet, supplemented by several grain and diary feedings interspersed throughout the day (a gallon of milk a day as the norm, to give you an idea!).

When thinking about the anabolic properties of a diet, let's not forget that the master anabolic hormone is insulin, and nothing will get it as high as a diet which includes high carb feedings every 2 to 3 hours, no matter how unhealthful it is!

Anyway, on a low carb paleodiet the anabolism you get is of higher "quality" (so to speak): 
you have more growth hormone peaks which build muscle and burn fat, whereas insulin builds both.
Also, a paleodiet seems so much more healthful that a diet heavy on diaries and grains that there really is no debate: 
You have to stay alive to enjoy the anabolism of any diet!  :-)