I read Along Came a Spider years ago (YEARS lol) then I grabbed Kiss the Girls one day... awesome book, so I had to go back and read Along Came A Spider again to refresh myself.. I have read the entire Alex Cross series since. However, I think the last couple have just been forced out.. they are good but too much jumping around in them lately, I dunno - can't really explain it, other than the characters aren't really evolving enough or to a degree that I would enjoy. Now his Women's Murder Club series is also very good.. but you have to be into these type of books to enjoy his stuff for sure.
As far as the book not being repetitive, no not really, but they have been getting predictable. I used to read Danielle Steele, years ago, but gave up because her books all followed the same format and it was tiring to read and that is how I feel about this latest Alex Cross novel, Mary Mary.