Let me start by saying that the Hotel Keizershof has large, lovely, clean rooms with great views, is in a prime location, and serves a wonderful breakfast. Would I stay here again? Yes. Was it without problems? No.
You need to know right off the bat that this is not a hotel, no matter what they call it. This is a B&B. Don't expect a front desk with services; you're staying in someone's home with no phones and family members milling around. That's fine, but they do represent themselves as a hotel, and it's just not true. Yes, they do have a lounge with a t.v., but we were never invited to use it; usually the owner's daughter was playing in front of it and watching cartoons while we ate breakfast 5 feet away.
Also, forget the "4 rooms" and "65 euro" that you will see advertised elsewhere. They now have, as far as I can tell, between 8-10 rooms, and no room goes for less than 90 euros, even in the off season. Also, be aware that the fact that you are in an old house means thin walls and very creaky floors. Ask for a room on the very top floor to avoid the noise.
On the up side, the breakfast was wonderful, the rooms are quite clean and definitely huge, the views are great, the family is eccentric but friendly. If you like the European B&B experience, definitely stay here. If you need hotel amenities, try somewhere else.