We stayed in NH Den Haag for two nights and we found it pleasant enough. We didn't order breakfast so cannot say anything about their restaurant (except that it looked expensive) but we've really enjoyed the fact that the rooms were spacious, modern and the location was very quiet. We've stayed in Amsterdam after that and paid twice the price for the room that was twice smaller so we really got to appreciate how spacious our room was.
The hotel is only one tram stop away and quite easily accessible by foot and bike. The fact that it's by the station means that you're within easy and quick access not only to the center of The Hague but also to the rest of the country, which sold the deal for me, as I've spend my time between Leiden, Rotterdam and the Hague.
The only thing about design is that the glass door to the bathroom serves also as a door to the toilet and while this idea looks great as design solution it reality it's rather...embarrassing as it provides no sound proofing.