For a group of more than 2 I would go for an Inn room everytime. Having proper beds is an important issue IMHO, but also depending on the age of the kids, it's possible to leave them in the room ( or leave them to watch the movie on the TV in the lobby) if you fancy a couple of drinks in the bar. That way they only have to walk through the lobby of the hotel, not through the grounds.
For a stay of more than 4 days (assuming 1 or 2 people) I would opt for the studio as I'd favour the extra room and option of having a "sitting area" .
For a short stay I'd probably take the convenience of the Inn room as it's not really worth bringing in emergency rations ( AKA beer etc) just for a couple of days, IMHO you may as well have a couple of beers in the Green Cabin and stumble upstairs to bed.
The studios are probably slightly quieter and a little more private if you think that is an important issue, but unfortunately there is no guarantee in any hotel/lodging that you don't get a noisy neighbour that upsets the normal "status quo".