The room was very clean and a reasonable size compared to similar in Reykjavik itself. I stayed just for one night before heading off on my travels around Iceland, and it was perfect. My flight arrived late, so I didn't get to go out for dinner. The yoghurt and muesli bar were therefore very welcome, as they kept me going until the morning. The next morning, I took a wander through the town and it's obvious that there are several options for dining within very easy walking distance, which makes it very convenient for an overnight stay.
The beds are very comfortable and I slept soundly. The shower is hot and powerful. I'd prefer a screen rather than a shower curtain trying to stick to me as I clean, but that's only a small niggle.
In all, I would stay again if I needed a night in Keflavik, and would happily recommend it.
There is a bus station within walking distance with a semi-regular bus to the airport. Due to my late arrival and the fact it was raining hard the next morning, I chose to take a cab. Note that these are expensive compared to many places, and I paid around €40 each way, for a ride of less than ten minutes. That seems to be the going rate, and I took it for convenience not necessity, but something to be aware of if you're on a tight budget.