mm I'd try em on somewhere -I'd still say the large is a 'small' large.
(Like the Prism Jacket/Fireball - I'd need an XL for them whilst everything else I have is large)
I tried a medium Prism Pants In Go Outdoors over my 32" waist/medium trousers and found them too tight all over. Had to go to large to get a size I could sit down in comfortably..
If I'd have bought medium mail order I'd have been disappointed. (unfortunately I didn't buy em at the time cos I should have been Christmas shopping - they'd have only been £56with theprice match - Outdoors Warehouse was doing them cheap at the time)