Just had a look at the Mudhugger – they look like they’d clog up really easily as they leave bugger all clearance around the tyre.
I’d wager they’d be useless in somewhere like the Cotswolds (from bitter experience) or anywhere else with proper claggy sticky mud.
You might think that, but mine worked fine in a mixture of Chilterns clay and gravel that stopped at least one other rider’s (mudguard-free) rear wheel from turning.
The only limitation I’ve found with the Mudhugger is that coverage varies a bit with seat stay angle. It worked fantastically well out the box on my 456, but when I swapped it to a Nicolai Helius the lower seat stays meant I still got a wet bum… A small mud flap to extend it cured that, though.