Can play new area in NG+ easily if you want, it adds about 12-14hours total.
Frostclaw/Fireclaws are fucking crazy HP sponges(I have figured out how too cheese Frostclaws, but Fireclaws seem to have a bug(or it's a design decision) were Freezing effects don't last long enough too really do any major damage)
Daemonic strength of the machines increased armor values, and increased resistance to electrical attacks.(you can still pop sparkers too get the effects)
The Tallneck for the area is fun(very different vs the other tallnecks), hunting grounds are pretty interesting, but the Control trial is on the scale of "Critical Strike" tied down glinthawks frustration.
There seems to be some kind of spawn problems with the new machines, you learn the override codes after finishing the main part of the DLC but I've only found 1 Fireclaw (Daemonic makes overriding impossible), Scorchers are interesting, basically upgraded Ravagers, with a mine launcher.
Overall it's a very well done DLC, answers some questions but at the same time leaves a bunch of unanswered quesntions. And it's very interesting seeing what they did with Yellowstone, I use too spend a bunch of time there every summer(my dad was an outdoor nut)