We are doing a split stay on our upcoming trip. 8 nights at AKL then 14 at BC. The reason we are doing it is we cannot make a reservation for longer than 14 nights so we may as well move

. Also I really wanted to stay at BC this time and my DS really wanted AKL. He loved it so much last trip (well we all did) so I thought he can have a few nights at his dream resort and as my very favourite restaurants are at AKL (Mara, Jiko and Boma breakfast) and wanting to do the safari, that's why we decided on that.
On our last trip we stayed at AKL for 21 nights, so as you can not book more than 14 nights in one reservation we had to have two reservations. We still had to check out then check back in, but I mentinoned it when we checked in and also went down the night before to say that we were not moving rooms!

So I left everybody in the room, we didn't pack up and I went down to check out then check in. Luckily they did let us keep the same room!
But for dining credits, having the two ressies was a bit of a pain, as they expired mid way through our stay, so we had lots of snack credits and a few CS credits left so had to race and buy heaps of CS snacks to store and use the credits as they expired at midnight when we checked out on our first reservation.
My mother came along on our last trip, but she was coming for the last 10 night, also staying at AKL. She ended up coming about a week early and had trouble getting accommodation when she turned up early, so the first night she stayed at AKL, then it was full, so she moved to Saratoga Springs for two nights, then she moved to Beach Club for a few nights before returning to AKL for her original 10 night reservation.
So she had to move from AKL to SSR to BC to AKL within 10 days and it was a total breeze. Bell services would come and take her bags the check out morning. She would go over to the new resort in the morning or afternoon and check in and then the bags were delivered to her room. Not once was there a problem.
For me the packing and unpacking is a pain. But I look at it as two different destinations

But experiencing my mums transitions the three times in one trip and it was all very easy and uneventful so I am not worried about changing resorts at all.
The problem occurs with tickets also. As if you want to do a package with dining on both ressies you have to buy tickets on both ressies (unless you are an annual pass holder, then you can do room only with dining). Tickets for the first two to three days are the most expensive, so if you have to do that twice it can get expensive. So it's best to do a package with dining on the first ressie but then room only on the second. Problem with that is if you want the dining plan.
For our trip we have package on the first AKL ressie with tickets (no dining plan, we are doing TIW), we are upgrading the tickets and our
Disneyland AP's to the Premier Pass, then the second ressie at BC is a room only ressie (no dining plan).
I personally love the idea of a split stay if you are there for long enough. I wouldn't do it I don't think for under a 14 day stay, so I could do 7 at one resort and 7 at another. But that is just my personal preference because I really hate packing

I'm happy unpacking, its the packing I don't like. You get to experience a couple of different resorts, you can safe a bit by maybe trying a Mod then a Deluxe. Disney really does seem to make it quite easy to move resorts. Its just organising it and working out what works for your family best in terms of Dining plan, tickets etc with your split stay.