So water is getting down their etc..was thinking of getting my first winter suit, saw a hyperflex flow hooded suit 6/5/4mm

1.) Anyone got anything to say about this suit? Crap? Good?

2.)Why is the hood only 4mm, I would of thought it be more or does your head just not get as cold as your body?

As I said first winter suit, so any tips or cheeky tricks would be great.