I found that really informal comments cut less deep 'hey man this needs double checking, read up on $x and then reconsider this block' (gender aside) is far bet

I found that really informal comments cut less deep 'hey man this needs double checking, read up on $x and then reconsider this block' (gender aside) is far better received than 'This is missing fundamental concepts around $x read up on them then rewrite this block'