I've got 2 for a chunky WB, the only thing I've had to do is replace the leg straps. But he does break them for fun! For a cheap rug (ebay) they are fab.
Love them - i have 3 - 2 are 5 years old and they came from ebay i believe Ridelo-uk is the seller all for less than £40!! i think they fit quite well .
quite generous fit
couple of the girls at last farm used them, one on a big cob.
Again leg straps snapped quickly, but seemed quite waterproof for a rug that cost twenty quid.
I have axiom rugs, buy them off a particular seller on ebay, they have served my mare very well, one of them is in tip top condition apart from the mud etc after 3winters and it cost me 12quid! Great quality, no leaking, all you need really