Personally GZ is my favorite base and it isnt difficult to attk maybe thats just me...
attking wise the bottom area kinda becomes like a spar arena if you know how to dodge you win defending wise you have strategic points that you dont give up and it became harder to defend with two entrances to the bottom area just before the flagroom which was a awesome addition but too many entrances into this area will make it perfect for ppl with more numbers to easily take then it will become like emines and no one would go there lol