During an organized bus tour through Iceland, I stayed at this hotel for one night.
This was probably the smallest room I have ever stayed in. As a solo traveller I got a single room, and the room was about the size of twice the (single) bed, meaning half the room was taken up by the bed. The rest had a desk, a table for the suitcase, a wardrobe and a bed table. Needless to say, the room remaining for the guest was miniminal. With the suitcase on its table, I had a to squeeze between the wall and the suitcase in order to exit the room or use the bath room. Cleanliness was okay, but not outstanding. Some towels had stains, and the bar holding the shower head was also quite badly stained, although in both cases I'd say these were stains which cannot be easily removed. Also, Wifi was only available in the lobby, not in the rooms. And it was very slow to use.
On the positive side, the food in the restaurant was excellent, everybody in our group enjoyed it. The service was very friendly and helpful. The room was quiet (once they turned down the music in the bar, which was around 11 pm), the bed comfortable and I slept well here.
It's an okay hotel to stay for a night or two, but if I stayed in Myvatn again, I'd first look for another hotel.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC