I had driven past Clevedon Court many times, but finally got around to stopping this past weekend. My husband and I really enjoyed our visit: the terraced garden was fun to explore and provided some great views of the house, and the NT volunteers were all so helpful. The introduction to the house was especially good (I have to admit I was previously clueless about the origin of the buttery), and the wardens in the rooms provided a lot of useful information when we quizzed them about the paintings and sculptures.
Clevedon Court is not a Stourhead or Kedleston Hall, but is worth a view if you're a National Trust member in the area (however, check the opening times first, as they're quite limited). I recommend following the visit with a cream tea at the Potting Shed Cafe at the Golden Acres Garden Centre down the road.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.