There is ABSOLUTELY NO difference except the price. The veranda is the same, the layout etc.. Cat. 5's are on deck seven. Personally I did not find that any more desirable than our cat. 6's on deck six or one cat. 6 we had on deck five. There are no cat. 5's on deck 8 only cat 4's "family suites" which are really cat. 6's with about three extra feet for a murphy bed and then the REAL suites cat1-3 (nope never been in one and probably never will, the photos look great though)
Go for the cat. 6 the extra money you save will buy a lot of konk koolers