Griezmann has deserved his semi-choker reputation despite half the problem being Atletico were really under dogs in those big ties. But he missed pks and few big opportunities in few of those ties to get some negative attention.
Neymar tho? Never got that impression with him, and trust me people have it so easy to dislike him that he would had this tag for sure if it was remotely close to true. He pretty much rises to the occasion club and international level, at Barca he carried them in several big games Messi or Suarez went quiet, in particular that insane comeback vs PSG. He saved PSG many times. He generally is very productive in most games, big or small. Even in national he has been stellar almost every time, except ONE big exception, last world cup, thats his first genuine complete and utter failure as a player in major tourno I seen. Even in the 2014 WC that was bigger failure at home for Brasil, he was individually great for them, so hard to blame. PSG go out in CL despite him performing strongly, not because he isnt (only blame he has for this CL failures is missing games due to injuries).
I genuinely worry about him solely for 1 reason, I dont even care about the attitude part, there have been many primadonna cunts in top footie that been dominating still, and he is still a fairly driven professional despite this dumbass character (so dont get the lolzillian part majorly effecting his career peformances yet, it isnt really). The ONE and only thing I worry about in signing him (besides being overpaid at 30m+), is his health for past 2 years. Before that he was super durable mostly, most kicked to bits player you can imagine since he was a teen, but he was mainly ok except minor stuff. But last 2 years been fairly significant injuries that held him back. Tho he has played 30ish games per season despite those injuries.