I took this tour recently with my husband and two teenagers. I would highly recommend. Our guide, Peter, and driver Jermaine (dubbed 'The Peter and Jermaine Show') were excellent - fun and entertaining, full of information and history, and very accommodating. My older one said they were the best guides we'd ever had! Peter actually took the time at the end of the tour to make sure each group understood how they would find transport back to their hotels from the dropoff point, and recommended other things to see and do during the rest of our time in England, which I thought was a nice touch.
Communication from Premium Tours was good. Note that there is a request to re-confirm 48 hours prior to the tour (we did it 24 hrs and it was no problem). At that time Premium told us what gate to go to at Victoria Coach station, which was very helpful as the station is a very busy place.
The tour itself covers a lot of ground, but if you haven't seen these sites before, you will get a great intro. I feel that the expectations on the tour itinerary (roughly 1.5 hours at each location) are set very well in the online description, and also by the guide at the start of the tour. The only deviation I noted is we did not drive by the Royal Crescent in Bath, but we had time to walk up there and see it ourselves, which was more interesting anyways. I would highly recommend purchasing any optional entry tickets for the sites (unless you've seen them before), as ticket lines are long and entering as a tour group makes things easy. Note however, that there is not much time built in for eating. We grabbed something quick in Windsor and again some take-away in Bath (based on recommendations from the guide). That worked out well, as it allowed us to get back to London a little sooner than the similar tour with the pub lunch.
There are a lot of day tour companies in London to sort through, some of which are 'middle agents'. Purchasing from Premium Tours appears to be a direct line - their busses were branded with the company name. I was impressed with how they operated, and highly recommend.
