I purchased this bed in the knowledge that I have a large, heavy cat (he's not obese, just naturally jumbo-sized). When it arrived I was instantly concerned as it didn't seem very sturdy and the hooks were so shallow that they wouldn't fit over a double radiator.
After finding a suitable single radiator (of which I have only a couple of) and putting the bed on it was an almost instant hit with my large cat. He slept in it for hours.
But it's fallen off the radiator - with him in it - a total of 4 times! I noticed that when I put pressure on one corner of the bed one of the hooks lifts up and the whole thing comes crashing to the floor, cat and all. Sometimes the bed's frame falls apart!
I'd only recommend this bed to people with small cats and plenty of single radiators. Otherwise you'll end up with an unhappy cat like mine who's torn between sleeping in his new bed and avoiding it lest it fall.
It also has very short hooks so people with high radiators should be wary, especially if you're buying this for an elderly cat.