We just rented a AKL Kidani Studio for 5 nights through David's DVC Rentals and everything worked amazingly well.
You can save a lot of money, and essentially stay in a deluxe resort for moderate resort money. IIRC we paid a total of $160 per night to stay at Kidani. Amazing value for us. I know going directly through an owner is even cheaper, but I appreciated the piece of mind of going through a reputable site with contracts, etc.
Everything went very smoothly- our reservation was in our name immediately, and we were able to get magic bands, Disney Experience, Magical Express, the whole nine yards.
I was a bit worried about getting tickets separately and linking them to the magic bands, but Disney makes it very simple- you just input a number from your ticket (wherever you decide to buy it from), and it is all set.
The major downside as others have said is you are locked in- so make sure your dates work! Also, if you want the really popular DVC resorts you will probably need to book 10-11 months in advance which can be difficult. We booked AKL 6 months in advance.
I would highly recommend it and we plan on using David's next time. Just have to decide what resort to put in for..