Like others said, I think it depends on your group. Are you all people 12-50ish in relatively good shape who don't have any medical issues? Go with standard. Are you older, have medical/mobility issues, are with young children who can't walk far, or will be dragging lots of heavy luggage? Maybe go with preferred.
Also something worth considering - are you bringing or renting a car? The preferred rooms can be a little far from the parking areas, and may not be preferable if you plan to hop in the car every day.
Also something worth considering - are you bringing or renting a car? The preferred rooms can be a little far from the parking areas, and may not be preferable if you plan to hop in the car every day.