Spent Christmas there with family group. Heavy snow, difficult access but arriving on Christmas Eve to this warm and spacious hotel on a mountain top was a romatic occasion (even the Christmas music was live and authentic). Rooms are large, a little old-fashioned perhaps but not disappointing.
That said, unless you go for the expensive set restaurant dinner, there are serious limitations. Bistro (expensive) has restricted hours and room service is very poor - one of our group who arrived late after a trying journey was presented with something frankly inedible (which in fairness was not charged). Breakfast buffet ran up to 11.30 but was uninspired. Koenigswinter has alternatives (e.g. the Jesuitenhof) but we would have needed our own snowplough.
This is really a conference hotel - but in a magnificent setting and with some serious history. Room rates are reasonable and younger folk made good use of pool and sauna.
- Steigenberger Grandhotel Petersberg königswinter
