I had them air fried before, and if you really inspect them and think about it you can tell they aren't chicken (from the texture but the taste is identical IMO). But I had them fried in a deep fryer this weekend and they were indistinguishable from real chicken nuggets. I am flexitarian so it's not like I haven't eaten a chicken nugget in years, they are legit. Definitely recommend trying them if you are trying to cut your meat consumption or even if you are just curious.
I haven't tried Impossible, but I always have Quorn nuggets in my freezer. If I really think about it, I can tell they're not chicken since they're only marginally trying to be. But it's a nugget, I'm not expecting a sous vide delicacy. Quorn definitely fills any nugget craving I might have.
I'll check out Impossible, though, out of curiosity.