Stayed in a pet friendly one in Yorkshire, with no pets. It was a filthy sh*t hole.
Supposed to be top of the range cabin - we had to spend the first night washing all the crockery and cutlery, mopping the floors, rinsing the greasy bin and fridge and cleaning the toilet. DS walked across the floor when we arrived and his socks were black. Full of pet hair, including the mattress. Even though they stated pets were not allowed upstairs, there were claw marks in the stairs. Had only four days in the UK and we were stuck with it.
Some of the cabins were very close together and our blinds in the bedroom were hanging off the rail. So not really the "away from it all" experience we expected. We were supposed to have a games package in the cabin - it was a scrabble box with half the tiles missing. You had to pay an extortionate amount to use the logs for a real fire, or suffer those hideous Economy 7 heaters. Front of hot tub balcony was covered in cigarette butts and bottle caps, and empty bird feeders?!
DH left his IPod on the bedside table, dashed back to get it an hour later and the cleaner (because apparently there was one) denied all knowledge of it.
Receptionist were mardy and the shop prices were breathtakingly expensive - and I live in Switzerland! 
Only upside was the hot tub, overlooking the slimy dirty decking to get to it!
Read the tripadvisor reviews - cleanliness comes up time and again. If you do want to go ensure you select a specific cabin. The one next to ours had new leather sofas and looked far cleaner. 
Sorry I can't be more positive. We paid a fortune and we were gutted.