Let's be clear there is no Blue Lagoon Kosher Hotel, it is the Capital Coast Hotel that an Israeli tour company has some kind of deal with where they resell rooms and they have a floor with a kitchen, dining room, coffee room and synagogue. The Capital Coast staff seem to have a natural dislike for the 'Blue Lagoon' guests and seem to go out of their way to be as unhelpful as possible towards them, I am not sure why.
You have to remember that there are other guests in the hotel, guests that are for Capital Coast, so as much as Blue Lagoon can try and set aside separate swimming times etc. this can't be enforced.
Staff - Reception staff were rude and unhelpful during our stay.
Rooms - we stayed in a Superior Suite. Huge room but lacked basic amenities such as a box of tissues, shower kept flooding bathroom and bed was really uncomfortable.
Food - The breakfast was really nice, Israeli-style with plenty of options but became boring after 3 days.
The dinner is very expensive - €45pp, wasn't really worth that though.
Hotel Amenities - nice pool and jacuzzi but my wife felt uncomfortable with all orthodox men around.
Also, the rooms look out on open square and can be very noisy at night with guests drinking/swimming/chatting etc.
Location - a bit out of the way and not walking distance anywhere nice.
Nice if you desperately need a kosher breakfast, but there is Chabad who offer meals and synagogue services so not a necessity.