We switch back and forth all the time. I judge a studio or 1-br based on it's 'value' to me for the particular trip. For example, we love to go to Epcot for New Years, but that's premier season, and if it's a weekend also, point costs can get quite high. So what we do is get a Studio for the high point days, then we move to a 1-br the first thing in January, (when everything drops to Adventure Season) for the remainder of our trip.
At Vero Beach we'll get a studio (in the inn). There we can enjoy the resort itself, and the room and experience is just like a regular hotel stay, but with a better room. We don't miss the 1-b/r there.
We've also used studios at BWV's as the atmosphere there can be very similar to a regular hotel experience and we tend to be in the room less often, instead taking advantage of everything in the area.
At OKW, we always get a 1-b/r. There, we tend to relax in the unit more, and we enjoy the spaciousness. To me it's really more of the home away from home feeling as opposed to the 1-b/r units at BWV and VWL.
In the final analysis, we do a 1-b/r whenever we can. That's the main reason we've done two add-on's since our original purchase in '93. You do get spoiled.