I have been lucky to stay in many of the Disney resorts over the years. We've stayed in most of the values, most of the moderates (except POR), some of the deluxes and one of the DVC resorts (but have seen the interiors and grounds of a few others).
In terms of Value vs Mod vs Deluxe I will say that for Value vs. Moderate to me the only difference in the rooms are theme, values have no hot tub, and no full service restaurant like moderates have (i.e. boatwrights). Now vs. Deluxe the amenities grow tremendously so if the amenities are something that is important to you then you will want to decide what matters vs. what doesn't. But I will say that in terms of sizing, that there will be great differences between resorts, and in price level.
For the sizing of the rooms issue, I would NOT upgrade into the AKL or WL deluxe resorts with a family of 5. The rooms are not much bigger then rooms at POR or POFQ and the quarters will be very cramped for much higher prices then POR. We were a family of 3 at the time and AKL and WL both felt like we were on top of each other.
We stayed at Poly and the rooms are larger but the cost to stay there is way over priced and that is because Disney knows that people want to stay there because of the Nostalgia, the proximity to the MK, and the fact that its a tropical theme. So they price it accordingly, unfortunately my frugal self won't stay there again. We had an AP discount and felt we had been taken advantage of even with the discount. We regretted that upgrade from a Moderate.
We were blessed with a free upgrade from CBR to Saratoga Springs which was a 1 bedroom Villa (not a studio) and the room was very nice spacious and plenty of sleeping space for all of us. The washer dryer was a great bonus, and the resort was very nice. We loved being able to walk to DTD, or water taxi to it, and the buses seemed to run pretty regularly. Had we stayed there and had to pay full price we would have a coronary because of the costs, the free upgrade was thrilling but even with a discount I couldn't justify the cost to do it. BUT I would totally rent points in a heartbeat to stay at either SSR or Old Key West.
We babysat my friends children one night for them at OKW so that they could enjoy a parents night out, and they had a 2 bedroom villa (dvc owners) and the room blew us away with how spacious it was, how nice the resort was, the amenities it offered, and frankly had the pricing for DVC been slightly better for our budgets I think we might have signed on the spot. But it just wasn't in our cards.
Renting through David's site is very trustworthy and is well known on the boards, saves you a bundle on rooms that normally would be well out of range, and will give you amenities you won't have elsewhere, plus you don't have to worry about if rooms will connect or not.
So my suggestion is since the only difference between a moderate and a value in my opinion is a hot tub vs not having one, I would get two rooms at a value with a request for connecting rooms, or book a family suite either at AOA which will give you 2 bathrooms and plenty of bedding and space for your family in one room or to rent DVC points for OKW in a 2 bedroom villa so you can save even more by having breakfast in the room, and maybe having 1 or 2 meals in the villa. To me none of the deluxe resorts are worth the price to upgrade from the moderates.