Stayed at Porto Sani Beach 5* for the last 3 yrs, can't fault it, and it has had a major renovations to the rooms there this year, the suites are like show homes now. Sani Beach hotel or Sani Beach Club? which one are you staying in, as both these feature in the Sani resort.
Sani resort is excellent, it is in the mid of nowhere, and not really typically Greek, but it s reassuring to know only resort guests can get in, and the marina is lovely for a walk everynight wiht the boutiques and bars, which some say are expensive, but that is down to the euro at the moment!

can't comment on actual hotel as not been to that one, but the resort is very family friendly and dsafe, great views and clean beach

The hotel is considered as one of the best and most organized resorts in Greece.
I would be confident in spending holidays there.

We stayed at the Sani Beach Hotel in 2006 and had a very enjoyable time. Room, food and pool all very nice and it's right on a nice beach. Had waitress service from the pool bar also, which was a bonus. On HB you can also dine at the Beach Club, which makes for a change.

We would definitely go back, but if I had to grumble it would be...
a. the place has zero Greek charm and is a little sterile, you really could be anywhere
b. drinks at the hotel and food at the restaurants in the harbour is expensive, even with the small HB credit they give you.

All in all though, it's a very nice and well run complex.