I have got sheepskin and merino wool ones, although both are cosy i love my sheepskin ones way more comfy and it just hugs your feet!The merino wool ones are warm and cosy to but tbh the wool has bedded down alot more than the sheepskin has, and ive also noticed that the wool comes out with my foot (i don't wear socks).
Re sizing i'm generally a size 5 but ive got 4's in the emu's, but even they vary (sorry to add to confusion lol) but my sheepskin ones are perfect but the merino wool ones are bigger could of got away with a size 3 in them!Both of my pairs came from asos in their sale practically half the price of qvc with quicker delivery!
Word of warning though, the tags inside are in a stupid place if you want to roll them over the tag will show, so been clever i cut them out :33: not so clever the stitching on the outside of the boot is attached to the tag therefore i ended up with holes on the side of my boot, spent hours sewing them back up!!