We booked one night in Delphi as a prelude to our tour of the Peloponnese with the intention of touring the ancient site. We had booked a suite and confirmed the same via email. We were expecting two rooms with a door between them.
When we arrived, we were shown to our room by the wife of the couple that owns this property. Unfortunately, she showed us to a room with four "twin" sized beds in it. At first, I thought there might have been a miscommunication, but then we decided to inquire and were hence shown to a true suite on a different floor.
The no frills rooms are very basic with very firm beds, but they were quite clean. The bathroom is small with the tiniest shower I've ever seen in my life, but it gave us something to laugh about. When we had settled in and decided to explore the town, the proprietress inquired as to our satisfaction. All was fine.
We explored the cute little town and had something to eat. Upon our return, we met with the husband, Ilias, whom I had communicated with via email. He is so friendly and will take the time to chat as long as you'd like. We really enjoyed the cultural exchange. Elias speaks near-perfect English. My husband is half Greek (but knows very little of the Greek language) and they enjoyed chatting for quite some time.
My niece was so taken with Ilias that she said she wanted to bring him home with her!
The hotel could be positioned in a better location as views from the hillside are simply magnificent, but the chance to meet and share some time with a local more than made up for any other shortcomings you might encounter. We enjoy the Rick Steves' philosophy of travel and I felt that we'd truly succeeded on this one! Too bad we only had one night to stay there.
p.s. Wish I'd taken photos of the inside of the hotel, but I'll just say the hotel photos linked here from Trip Advisor are accurate.

The hostel was good--very clean, good hot shower, good-sized room for four people. Wifi even worked on 3rd floor. 2 of the four beds a little soft. Street parking was easily available (in April) and it was a nice, easy walk to the ancient site. We liked that the hostel was two streets above the main tourist road and quieter. Breakfast was OK to good.

Unusually clean, comfortable, friendly. Great view out the room window and balcony. The owners are very warm and hospitable.
The breakfast was very good indeed. Highly recommended.

My brother, girlfriend and I stayed for 2 nights at the Hotel Castri in Delphi. After a long drive rom Nafplion via Olympia, we arrived late at night to be met by the manager. He was out of this world! Super friendly, cooked the breakfasts, etc... and went out of his way to make us feel welcome!

We got two great rooms (at a very cheap rate) and decided to stay for 2 nights instead of just one.

Breakfasts were included and simple.

The hotel was VERY clean, and the balconies had an amazing view over the surroundings at Delphi.

Location: In the centre of town, and close to shopping and restaurants. Delphi is a fairly quiet town.

The hotel was also very close to the ruins (Temple of Apollo), etc. You could walk there - it's less than 1km. We drove there because I wrecked my ankle the previous day.

In all, the owner made the experience at the Hotel Castri fantastic. It was a great example of Greek hospitality!