They definitely used a better version than the base 5e material. I am pretty sure they based most the ranger stuff off the unearthed arcana revision Ranger. I have used several of the beast summons and they all seem useful in their own way. They wont take a TON of hits, but they all do ok damage, and have their special skills that can help alot.
My personal favorite right now is the bear, at level 3 he has 19 HP (pretty decent), does ok damage, but can taunt enemies, so he will soak 2-3 hits before he dies, which is 2-3 hits my party did not take, which in this game is amazing. The Hunter will likely be better damage, but I like the utility and flavor the beast class has.
Since we don't have later levels, we don't know how well they will scale later, but at low/medium levels looks like they will be ok.
