the board is rated Adv to Expert but does this really matter that much??

From reviews i think this is one of the best groomer / hard pack boards, which suits perfectly to my riding environment.
I understand i wouldn't be able to enjoy the board to its fullest for now.

I'm 6", 220 pounds, size 12 and looking at the Anthem Wide 163.
The board needs to last for a good few years and i'm not interested in speed and ripping turns etc with occasional air.
Though this is stiff board, i should be ok to progress on this?

anyone with experience on this? the board size is ok? or should i just go for a beginners boarD?