I base my decision on cruisers reviews as to me the staff reviews seem to moreover match what you will find on a cruise line's site. Whereas cruisers will give you more opinions as to how the ship is. Sure you will find negative in these reviews but depending on what the negative is it is easy to disregard especially regarding food unless you find that the majority of people give food a negative. I usually do not pay attention to those that say things such as the cabins are too small as I know that unless you are getting a suite you will not have a large cabin.
I have found that it is not just on Cruisemates that I will find these types of reviews by both staff and cruisers.
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor Feb 2012, MSC Poesia Dec 2012, MSC Poesia April 2013, Carnival Legend Nov 2013, MSC DIVINA Jan 2014