Just did a split stay (WLV and BWV) off two david's reservations and it went without a hitch. It was only two of us, so the space of a studio wasn't a problem. We went in January though, so it wasn't too hard to get what we wanted.
Pros:
PRICE!/LOCATION! Staying at a deluxe location for the price of a moderate was the big deal-maker for us. With the exception of our day at animal kingdom (which was also the day we switched lodging), we didn't end up taking a single bus. We picked WLV over BLT because I'd always wanted to stay there when I was a kid and my mom couldn't stand the rustic theming

. We're going to do a 1BR at BLT next year. It's the only DVC on the monorail and walking to the MK is the ultimate perk. So, if you're an MK junkie who also wants a convenient way to get to epcot, I'd pick it. Obviously if you're more into Epcot/HS, I'd stay at BWV or BC. So much easier to walk back after illuminations/fantasmic than to fight crowds on transit.
The people at david's are really helpful. We gave them our top 3 choices, told us we wanted to a split stay, and they showed us pretty much anything that they thought we'd be interested in. A few months later we had flights, shot them an email, and they got our DME reservations and sent the packet. They respond really quickly, which is reassuring.
Cons:
Not being able to cancel the reservation is really awkward feeling when you have to book so far out. I think it was April when we booked for January. We always go in January and we don't have kids, so we were pretty confident there wouldn't be any situations to prevent us from going, but it's still a big commitment
I'm 2/2 with them so far, and I plan to keep using them year in and year out.