Big Fan
I've been a Birk Sandal wearer for years (kids XC coach recommended for back/knee/foot pain...and 100% correct), and decided to give these a go, and wow. I love 'em. For me, I went up a size from my shoes (US 11-11.5, purchased the UK45 [US 12-12.5]). Super comfy and supportive.
Fast shipping from Simply Birkenstock as well. Great experience top to bottom.
Thanks!