A rare response from Johnny Boy:
As applies to many topics on here the answer can depend on your circumstances, so there isn't a right or wrong way just what suits you best.
In our situation with Joshua's autism, he likes his home comforts and private pool and having plenty of room/cooking facilities are major plus's for us as we rarely eat out.
The advantages of just staying at a villa mean you can fully unpack and settle without the need to check in and out to somewhere else, which
depending on timings can mean you lose a day of your holiday, as you may have to check out around 11am and not be able to check in to your second location until 4pm or so.
So that is usually our choice. To be honest we don't mind the cooking, I appreciate there are negatives but the plus points outweigh them.
I can totally understand people who do not want to cook , shop for groceries or do cleaning on holiday, however it really doesn't bother me (mainly as Julie does it all

)..just joking as the driver
I do the shopping bit.
With Josh being an early riser that would be a major worry with people in the next room for 2 weeks. At a villa he has the freedom to express himself!
Sure there are downsides - the isolation factor - we have had holidays where on the development I haven't spoken to anyone except the 'pool guy' so choosing a gated villa 'resort' can mean you get clubhouse facilities, which may include internet cafe, communal pool, children's playground etc so the opportunity is there to interact with other children.
I don't think I would fancy a hotel stay for 2 weeks if we had more than one child, it would be just too cramped, especially as relaxing to a degree plays a part in our holiday too as we rarely get the opportunity to at do so at home.
I agree a split stay is a good option, but the checking in and out twice scenario can be time consuming and unsettling for the children *especially if they are like my boy!*

My personal choice for our next holiday would be the first few nights at Grand Floridian, with the rest at a villa at either Windsor Palms or Windsor Hills.
However, that is based on my needs to enjoy some evening entertainment on-site, whereas Julie and Josh are happy staying in.
After 5pm or so he just wants to wind down and chill, whereas I want to go out..it's a surprisingly difficult problem which to date I still haven't solved, so I suppose for me that is the biggest problem unique to me/us, getting out of the villa in the evening as a family, I have lost count of the number of times I have gone out alone.
That's partly why we chose Terre Verde for this April's holiday, however it didn't work out quite as expected as the 'Tiki Bar' was either closed, or not
quite what I expected. Cue me getting 'dressed up to kill' only to find everyone else in their swimming costumes (well the other 2 people that were there).
The GF , where we took loads of photos, looks more like my style, but Josh looked less impressed when we looked around so.....
Staying on-site the real advantage is the location, being close to Magic Kingdom is very appealing for example. I have never stayed POR or looked around there but as with any Disney hotel being close to the action is in my opinion the big plus.
I can relate to what you say about being "spoilt" it's like flying Premium Economy, you never want to go Economy again.
I think you need to decide if you want to settle down for the full 14 days in one place, or if you are happy having to pack/unpack and have the additional check in/out issue.
If this doesn't bother you then the split stay is definitely a sound choice. I just wish for us it was that simple.
In your circumstances I would consider 4 or 5 days onsite at your chosen resort, with the rest in a villa.