Check out @CaitoGalenus’s rundown of the new Necron stuff available for pre-order: Necrons Unleashed.
Speaking for myself. I quite like the new Necron infantry. They have a very definite style with plenty of options without being over the top and it looks like you could have some fun choosing a cool colour scheme that suits both your taste and the new models.
I’m less keen on the new vehicles. the Catacomb/Annihilation barge is okay but I don’t much like the look of the Ghost/Doomsday Ark.
The character models are cool, and speak to the new direction GW are taking the Necrons. I think this is overall a good move for what had hitherto been quite a bleak and characterless race.