I agree totally with Mike.
My three reveiws have been on one ship, Explorer of the Seas.
The first one was effusive in its praise of just about everything but then, it was my first cruise. Yet truth be told, I really found it that good.
I then based my two subsequent reviews on the first as regards the major issues. The second was still what I consider a "good" review but things had started to slip.
By the third review, things, especially the food, had slipped badly. That is not because I became more discerning but rather because it was not up to the standards to which I had originally been introduced.
Having said that, I enjoyed all three of my cruises. I have never had a serious complaint about staff or crew. That might well be because I am a "people person" and try and be kind and not overly judgemental unless the situation really deteriorates with one or more individuals and that just hasn't happened to me. Then again, I've only cruised on one ship and each time the same itinerary. Since Fran and I were guests of her niece, we went where and with whom she wanted to cruise. As a matter of fact we had the same class of cabin (oversized outboard over the bow) and actually occupied the same cabin itself back to back on the last two cruises.
I had always thought I'd never cruise again after Fran died but I have since changed that decision based upon something that I wish not to share at this time. That cruise will in all likelihood be on a different ship with a different itinerary from a different port so I'll be able to truly compare differences.
While I do not read Blogs, I do read professional reviews. I have found that Paul's are more in depth and sometimes more critical simply because he has the experience which most if not all of us don't and that is that he actually worked on cruise ships.
So in essence, I use three facets; personal past experience, reader reviews and professional reviews and will be using all three for comparative purposes for any future cruise.