I had done a lot of research before our trip to Yountville, and David Locke/Wine Consort Tours came highly recommend by other travelers. We booked with David over the phone a couple of months ahead of time and spoke to him a few times before arriving in the area. Although we never received an itinerary, we had talked about what we would like to do during our day. I had mentioned going to Sonoma and perhaps going to a cheese shop in addition to the wineries, just to break up the day. As our tour day approached, we were really looking forward to meeting David and driving around in his Escalade and learning about the area.
When our day arrived, we were greeted by David's wife, Susan, and we were not driven around in an Escalade, but in a Jeep Cherokee. Don't get me wrong: Susan was very enjoyable and kind and gave us a lovely day (and frankly three people don't require an Escalade), but it was surprising to receive a completely different experience from what others seemed to have gotten and what we had come to expect.
We did visit several wineries in the Saint Helena region, most of which were smaller and family-run, which was really nice. You definitely get more attention and learn more about the wines this way, which we appreciated. Susan made sure that none of the places we visited had a hefty price tag for their tastings. We did have a tasty lunch from Bouchon Bakery consisting of chicken salad sandwiches and oatmeal raisin cookies, which we enjoyed at the Salvestrin Winery.
We never did make it to Sonoma, but we did have fun getting to explore the northern parts of the valley. The countryside is beautiful, and Susan was a great person to spend the day with.
I would recommend this as a nice way to spend the day either as a couple or with a group of friends. If you have somewhere you absolutely want to visit or you really want your tour to be with David, then I would suggest you confirm that a day or two before your visit. The only reason I gave it a "very good" rating as opposed to "excellent" is because we didn't quite get the experience we were anticipating.