I've been to Kronberg and it's beautiful. If you arrange it in advance, you can have a tour of Vicky's private rooms. I and my friends were shown her bedroom, and a bedroom used by Willy, as well as sitting rooms, where some of Vicky's paintings were hung. The bathrooms were comparatively modern, and you can actually sleep in Vicky's bedroom, however, as you can imagine, it's extremely expensive. Don't expect the guide to be conversant in the history of the place, he showed us many photos which he mis-identified (we kept our mouths shut, afterall, they were showing us hospitality!). The grounds are gorgeous, but because it's a hotel there are golf links and places you're not supposed to walk. We did take shots of the famous steps where Vicky, her children and grandchildren were photographed. As we had lunch there (unbelievably exquisite and worth every Euro), we were allowed to look around. It's very homey for a castle, and I understand why Vicky liked it.