I echo some of the previous positive reviews. This is our 5th cruise and yes it's not luxury but it's not Butlins either. We have cruised with Princess recently so are able to make a comparison with the more luxurious ships.
The staff were great. The bar and restaurant staff are friendly and the ones that look sad are probably home sick so chat to them and take the opportunity to learn a few words in their native language (often Russian) and they will go out of their way for you - no tips are required just a smile and a bit of effort.
The entertainment was mostly fab - Carly (Carlotta) was my favourite - she could sing and dance and act - really passionate and enthusiastic about her work - so infections and positive.