The site is breathtaking and worth the time it takes to get there.
Our guide was very knowledgeable and even gave us the odd tidbit as we traveled to the site.
Once at Delphi, the tour can move at pace (there were several other groups overlapping each other) and information comes thick and fast. Our 9 year old daughter loved it!
We chose to walk on up to the ancient stadium, the site of the Pythian games. Again this was well worth the extra 15 minutes club, but it used all (and more) of our available "free time", so we ended up missing the start of the guided museum tour.
The museum tour was, as with the previous part, delivered with real knowledge from the guide. Again though, we could have done with maybe 10 or 15 minutes more to do a little free exploration.
The restaurant was warm and welcoming with traditional Greek food. Importantly, there were decent options for vegetarians.
Overall a very good experience and would recommend, but perhaps an additional hour would make the site visit perfect, especially if going at busy times.