World class gets bandied about a lot on here. Very few world class goalies in the world at any given time. Sadly I don't think McGregor has ever been in conversation.
Stack him up against his peers past and present, during his career and he's not in that conversation imo. If he was why didn't he play for a top side in England, Germany, Italy or Spain? He had the opportunity to when he left Rangers in 2012. He went to Turkey and then after that ended up at Hull.
An excellent keeper, but World Class? Nah, not for me.