We stayed at Mo's for two nights and it was fine - we didn't spend much time there anyways since we were busy getting to know London. He was incredibly easy to get hold of ans always answered promptly, big plus!
He seems to be hosting a few people at the time which wasn't a problem at all, it's just good to know especially when a few people want to use the same bathroom in the morning. Everything was very clean and tidy. There were some stains on the duvet on pillows but I'm pretty sure they were old and everything seemed freshly washed, so no problem.