From what I understand, YC is quieter than Beach Club, so that may help you "wind down" at the end of your trip. If your kids like to swim, the pool at BC/YC is great! You can
walk to Epcot and take a boat to MGM so you will have a nice close proximity to parks like you did with AKL (just different parks). You will two queen beds which is nice for the kids.
SSR is close to Downtown Disney, one of the places I like to visit towards the end of my trip. Great time to get some last minute shopping and taking in the sights without going to the parks. But SSR is not "in the middle of Disney" like YC is. A 1 bedroom is going to give you a king bed in the bedroom, with a pull out sofa in the living room for the kids (not so great for the kids, but really nice for the parents

) You'll have a full kitchen, in case your sick of restaurants by then. But if you're on the dining plan, you're not going to need it. BUT after a long trip, you might appreciate the washer and dryer and could do laundry from you room and come home with a bunch of clean clothes instead of mountains of stinky dirty clothes.
SSR is nice, but if it was my decision, especially considering you originally had a resort room to begin with, would be to go with YC.
I hope that helps a little.