SSR - 2 beds NOT preferred - but I am OK with walking, we don't plan to eat breakfast at the resort unless it's in the room and I can walk on the resort day to the pool (well, I say that now)
GF - 2 separate rooms for the first part of the stay and then when my husband leaves for his work trip my mom will move into the one remaining room and there will be 2 adults and 3 kids in one regular room at the GF
WL - 2 separate rooms the entire stay
Of these, I personally would rule out GF. I don't want to try to cram five people in one hotel room for half the trip.
And we are doing all 4 parks.
Nothing is close to everything. If you've never stayed in the MK area, you'll be surprised at how "interesting" it can be to get from there to all of the parks not named Magic Kingdom.
I'm a big fan of the Villas, and I like SSR a lot. Now, I
also like WL a lot---and it might be possible to swing a 2BR at either Copper Creek or Boulder Ridge for not a whole lot more money, particularly if you are renting from a DVC owner.
i think it depends on the vibe you are going for.
SSR/Villa advantages: the Villa is qualitatively more comfortable and convenient than two hotel rooms. There is a place where everyone can gather, plus places for everyone to retreat to if they need to. The "home away from home" features make some things just more pleasant, even if you don't strictly "need" them. For example, on my last day I often throw some laundry into the washer on my way out to the park that day, so that I don't have to unpack luggage full of dirty clothes when I get back. That is
certainly not necessary, but it is awfully pleasant.
WL advantages: a much more prevalent theme, and a fabulous location on Bay Lake. A little more energy than SSR, though not everyone would consider that an advantage. More easily accessible quick service if that is important.