Just as good as the capsule hotels I've stayed at in Japan, with the added bonus that they give you, on request, a small USB fan to help stave off the usual "hot and stuffiness" that comes with staying at a capsule hotel, which I've never had in Japan!
All the staff were fantastic, every interaction was friendly and helpful. There's usually space in the communal area downstairs to sit and hang with a drink, and they have a fridge and full kitchen if that's your thing.
The bathrooms and showers are clean and plentiful, I always had my pick of showers. The lockers are just about big enough for a large backpack but not really big enough for a suitcase, so the room had a few suitcases against the back wall. Not a problem, but worth being aware of if you're paranoid about your socks being stolen.
Would definitely stay again.