I find his basics to be flawed. Like he has always been a brilliant athlete and has relied on that to get him as far as he has so far.
My biggest worry with him has always been an issue I have with a lot of goalkeepers, namely some goalkeepers always seem to guess where the ball is going rather than reacting to where it goes if that makes sense? I see it with Pickford a lot, lets say a low ball gets put in across our six yard box, he will always throw himself down to where the ball is roughly going without waiting to see where it goes. That's fine if the ball ends up where it looks like it is going, but if it takes a deflection or gets blocked and bounces to another player etc, the goalie is already on the ground and has left his goal open.
I always look at the likes of David Seaman in his prime, maybe not one of the best ever but a very good goalie who very rarely made a spectacular save because he waited to see where the ball was going and would calmly collect it. Southall was a nice mix of both as he also had the reflexes to pull of ridiculous saves but could also make hard shots look effortless due to good positioning.