My opinion, FWIW:
I like to try different resorts on different trips (or even with a split stay on the same trip). So, my inclination is that it is fun to try something new. All resorts are unique at Disney and each is special, IMO, in its own way. However, not every resort is right for everyone. Also, you have stayed at the Poly and know that you love it. In the end, you need to do what will make your family the most comfortable and happiest.
So, you say that you are reluctant to try somewhere else. That confuses me a little. I guess that by asking about staying somewhere else means that you would like to try something new but you are afraid that you won't love it like you do the Poly? Or is it primarily a budgetary issue? Something to think about as where you choose always is impacted by budget, in my experience. And a comfortable budget always outweighs other concerns, IMO.
If you are like us, you will love any resort, but you will probably prefer the Poly at the end of the day. It IS that great, IMO. However, not everyone feels that way. PLUS Even though I do prefer the Poly to most other resorts, we only stay there on occasional trips. That is because we love variety more. Would you prefer to spend a portion of your trip in a known comfortable surrounding? Or do you feel a bit adventurous this time around?
I would like to note that, unless something has changed recently, POFQ does not sleep 5 but its sister resort POR does. If your budget is happier with a moderate this time, then POR is a gorgeous resort to choose. The rooms are significantly smaller than those of the Poly with a rustic atmosphere, but it is doable. POR does remind me of the Poly in that the grounds are full of foliage and beautiful. If the budget is stretched otherwise, then this is a lovely option. However, go in with expectations that are realistic and try to avoid comparing to the Poly. Yes, the rooms are smaller so it will be cozy, but doable. You know, I expect, that the rooms are motel style with exterior entrances and have no balconies? Plus, that buses are the mode of transportation everywhere - except DS. There is a great boat ride to Disney Springs that is very enjoyable. I would like to suggest preferred rooms at POR, if possible, due to the size of the resort.
The CR has the advantage of being a deluxe resort and is walking distance to the MK. It is night and day different from a stay at the Poly. However, especially if you can swing a tower TPV room, we love it just as much as the Poly. If the theme appeals to you and a simple pool isn't a deal breaker, then this would be my choice of alternative resorts to the Poly if budgetary issues are not an issue. The freedom of walking to and from the MK just thrills me every time we stay here. The view of the entire MK area takes my breath away. Watching the MK fireworks with little ones on a CR balcony is a memorable experience! AND,The rooms are just as nice as those at the Poly, IMO, or perhaps even nicer.
The BC is a great option with an incredible pool area that many people love. However, I would probably eliminate this option for the several reasons. Are you comfortable with the children being out of sight while swimming? If not, it can be tricky keeping track of them here. Plus, the slide is accessed outside the pool area. With three children, I would wait for a later trip until they are older to stay at the BC. But that is just me. You know your own children and your comfort level best. I enjoy a trip staying in the Epcot area very much, largely because we like to walk to both Epcot and DHS. Plus, The boat is always there when we are too tired to walk. Also be aware that, although this is a deluxe resort, some rooms seem almost as small as the POR rooms and some rooms only sleep 4. Balconies are sometimes too small to sit on and have standing room for only.
AoA is a value resort. The 'suites' are nice but this isn't a deluxe. If you are staying here only for the suite and not for the theming, then I would choose the CR or POR. The over the top theming is the big draw here. This is just my opinion, but we really enjoy the upgraded amenities at the moderate and deluxe resorts. Plus we have always been fine staying in one hotel room with one bathroom. We do stay at value resorts and enjoy them, but usually it is for park intensive trips or for budgetary reasons. This would be my last choice of the ones that you suggested.
Good luck choosing. All resorts at WDW are awesome, so you should enjoy a stay at any of them. It is fun trying them all, but returning to a favourite is good too. You can't go wrong.
Enjoy!
