Hi, we have (13th May) just come back from Sidari where we stayed at the Orestis apartments which are the sister apartments of the Beach Star Hotel. We had a great time and would thoroughly recommend the accommodation and resort to anyone.
The weather was great - only one bad day, which we took as an opportunity to visit Corfu town. Kassiopi is worth a visit - very pretty, as is Corfu old town - lots of shops. If you hire a car or want to take a trip I'd do it direct from the shops in town. The reps will offer to do it for you but will charge about 3 times as much as the locals for car hire and double for trips. Would recommend Mikey's Inn for drinks and family entertainment and the Roof Garden restaurant for good quality fairly priced meals (some of the restaurants serve dreadful food). The Mimosa hotel was easily the cheapest place for breakfast (including tea/coffee) at 2 Euros.
forgot to say - one of the best things about the apartments/hotel was the location. Right on the seafront - separated by a road (but one that's hardly used other than by pedestrians) in a very quiet area. However, you are within about 5 minutes (max.) walk to the main street with all the shops clubs, bars and restaurants. Easily the best spot in town. If we went again - which we might - we'd go to the same area if not the same hotel/apartment. We had two teenagers with us and we felt confident to let them go out till the early hours and then walk home.