Door to door service is the way to go.
My wife and I booked a Sidetrip transfer from Prague to Vienna via Cesky Krumlov. Our guide Filip picked us up at our hotel at the designated time. He showed us all around the beautiful town of Cesky Krumlov. He was knowledgeable and went out of his way to ensure we loved our trip. He couldn't have been more pleasant and seemed to enjoy the day as much as us. After a great day he dropped us off at the door to our hotel in Vienna. It's a memorable experience I would highly recommend.