HunterWomen's Play Tall Rain Boot

Are hunters true to size, or do I need to size down?

How tall are size 5

How flexible are the boots? Don't like feeling my leg is in a splint - lol. Also, do they run small or large? I'm hesitating between size 4 or 5.

There are 2 pairs of red wellies, differing in price by £10 but can't see the difference. I want the tall ones. Can anyone help please?:)