Geralt needs the cat eyes. If they dump that then I'm not watching the show. There are some things I will be unyielding over.
I don't think Cavill needs an American accent as Geralt, and I'd rather he not use one.
I think some hardcore fans were hoping for someone like Mads Mikkelsen, who Sapkowski once said he sees as Geralt, or Nikolaj Coster Waldau. Both choices were unrealistic.
My main choice was Zach McGowan. At least he expressed interest in playing the character.
As for the casting, to be perfectly honest, IMHO, Geralt is NOT a hard role to play. He's Mr. Gruff Tough Witcher. Rough and gruff on outside, but on the inside he's a gentle soul with a heart of gold who cares for his friends and loved ones. Others have already mentioned this here.
I mean look, Cavill has already had tons of practice playing the dark brooding loner as Supes, right?