Well Brooklyn took me and a few guys I play with 6 hours on Heroic diff... its not bad, just not worth 5 years of waiting for new content... is it worth it? Yes but they really screwed themselves Ubisoft by closing development, letting the team go to other projects and then outsourcing development to other Ubi studios.
The assets are ALL reused, buildings, enemies, no new mechanics really... the have put back in smart cover, but its not really anything new... the story lost me ages ago because they decided to kill Keaner after WoNY because they thought the franchise was dead with the closure of the game development and then had to bring the main bad guy back with some weird ass story.
I have played over 3k hours in the game and the only reason I play it is to talk to a few guys that I have played with from the beginning. They missed a trick not setting it in the snow I think but Yannick is dead set on having no real connection back to the old game, he said that at the development start of TD2 and has mostly kept his word.
If you do like TD2 then yer defo worth it but taper your expectations as there is nothing new really in it, nothing you do will make you go wow that is amazing or that is cool, same mechanics, you walk through the missions going this is from that mission, this reminds me of that mission, ow they used that from that other mission, but its different enough I guess, but just more WoNY really
Stelly