If you get 2 rooms there is no guarantee the rooms would be adjoiniing or close to each other, in a suite you'd all be in the same rooms.
In rooms there are 2 double beds, 1 table & 2 chairs. In a suite there is 1 queen, a couch that folds out to a double bed, a chair and ottoman that fold out to twins, one table with 2 chairs.
In a suite you get a small kitchen area with fridge coffee pot and microwave.
I think the extra cost is about what a fridge for a room would cost.
Choose by what's more important to you.