I think it depends on your circumstances. When we 1st stayed at OKW, we were in a studio, DW, me and our DD and DS, who at that time had no issues in the same bed, they were too young to understand differences in boys and girls. But my DW and I quickly decided if we were to ever stay at OKW again, it would have to be in a 1 bed. Our only other comparison to a studio would have have been at Villas at Wilderness Lodge(aka these days as BRV). Even though OKW studios have more SF, VWL felt bigger and less like a nice hotel room, but more like a true villa or efficiency apt.
FF to a few years later, we got a 1 bed at OKW after the kids were getting older and we had began to experience 1 beds at VWL also. WOW, just WOW when we walked into the 1 bed at OKW, it was HUGE, with a very big balcony to boot! The living room/kitchen/dining area was massive, plenty of room for our kids to spread out, and each had a bed, DD took the sofa bed and DS took the seat bed. We never looked back at studios again(though we did stay once at AKL for a quick stay with DS). At that moment, we fell in love with OKW. At that time, VWL was and still is our home resort, but OKW quickly became a really close 2nd in our hearts.
You asked, what makes a 1 bed worth it, So I might get blasted here, and its just my opinion...Studios at OKW feel like a glorified Holiday Inn room, meaning, no where to set as a family except the beds if you are watching TV, in other words, no couch. If I were hitting the parks early, staying late, all I need is a studio, anywhere. But Im fast approaching 60, and the days of hitting the parks wide open are long gone. 1 beds and 2 beds at OKW give us room to move around, have our own space at times, laundry, which means less to pack, and the plus of 2 beds over one, 2 baths instead of 1. Thats a plus where 3 adults are going like our family is these days(DD is married with 3 kids now)so DS is right there with us when we hit the road to WDW. Another plus in a 1 bed, to get ready in the AM, my DW can utilize one shower while I am in other, coming in the evening and 2 folks need a toilet(not trying to be crude, but lets face it, as we age, toilet needs are more prevalent

).
Its little things, but we are on vacation, I like to feel as if I am. Too many times we put ourselves in cramped spaces with those we love the most when on vacation, and we come back not feeling rested, but rather tired, and too a degree, tired of each other. A WDW trip should be about making memories with those we love, and keeping those memories alive well after those we spent the time with are gone.
DVC does cost a lot, I agree, wish we could go back to the $50 per point that my friends bought in at OKW way back in 91, or even the $72 per point we paid for VWL 10 years later. Those days are gone. But I cant put a dollar amount on all the trips we have made, and raising our kids partially at WDW, or the times spent with my parents as they were aging or taking my Dad to see the Atlanta Braves at spring training, or having the MK mayor walk our DD back to City Hall to get her birthday badge, all the while yelling her name out as others were entering the park and having them all holler back, Happy Birthday Kristian! Lots of other magical moments that occasionally hit my brain and it makes me smile. WDW and DVC created another life for me that otherwise I wouldn't have had. And I have no regrets at all!