Choice is always good: X in a big bus, various Small Group operators - for us both have the same disadvantages in that we have no control over the itinerary, pace or stops. Or, our choice, ToursbyLocals. We deal direct with the guide, personalise the route, stop for coffee and cakes, split the cost with one other couple (sometimes 2 other couples) from the Roll Call, pay via the "lovely ladies" in Canada and get a full refund if the ship fails to dock. We have used TBL in Japan, China, South America, USA, Europe and never had a bad guide.