Let me preface this with this big statement: I don't believe I've played a beastmaster at hero, though I've toyed around with them in the mid ranks. I have fought some as a few different characters.

Really, it looks to me like this comes down to playstyle difference. If you want the big ambush followed by a potential snare and second ambush or call lightning, beastmaster is definitely not for you. You should be playing a savage.

The big advantage in my mind with something like wasps is that it doesn't allow them to rest and causes decent, continual damage (similar in manner to immolate, if not the same amount). If you can land a few entangles then land it and they flee and recall, there is a good chance they are still there sitting at their recall spot healing their health and moves. That leaves potential for planning for someone to sit there and be ready to bash. It really can be quite dangerous if landed late in a close fight right before someone flees.

I still think you are underestimating wolf kinship, more when paired with something like beast call. Tracking mobs that cause people to flee is excellent, especially in random mazes (Like outside outlander of HToS).

Both of these abilities get much better with outlander leader insects, though I am unsure if wasps would stack with it. I suppose that makes the build somewhat niche.

I wouldn't mind seeing the other abilities touched up, but as it is I still consider this one of the three best expertises. As much as ambush onslaught, prot vs metal, and mace are nice.. I hate having to give up metal and it can make gearing a lot less enjoyable - especially if you don't have any druid friends. That isn't to say savage is bad, it and survivalist are both good.

I find the idea of hunter being better as funny, as there have been two I've seen that are scary. I really can't speak to animist as I've never played nor faced one, but from all accounts they don't seem deadly either.

Really, if someone has the time go through the rangers based on pk record and determine their terrain/expertise it could provide some more numbers to actually fuel this argument. As it is, I don't see it as beasmasters are bad.. they just aren't savage good.