I think it depends most of all on the pricing: rack rates, available discounts, and time of year, but there isn't one universal answer.
A Deluxe at 40% off is probably a great value, while 40% off a vlaue isn't that much of a savings. A deluxe during value season is a much better deal than rack rates during Christmas. Conversely, A fixed discount like
free dining, is probably more of a deal at the value resorts. Then again, there is a HUGE variety in pricing among the deluxes and room categories.
Next up is experience. I think it's fun to stay at a variety of resorts. So part of my answer depends on where I've stayed on recent past trips. We had our first stay at Pop in 2007, and part of the thrill was discovering a new place! The Swan was a great value to us on many trips...but after a while we wanted something new.
The next thing I would say is time = money.
With little kids who must nap...the convenience of a deluxe is a big value. It becomes a great value. Likewise, in February changing into long pants at night is a must, location's a big plus. In April or October, it's easier to go all day, so closeness is less important.
When I travel with different family members the prioities change. One family memebr, insists on a large pool for laps. Another really values a hot tub. So even though the Poly is a deluxe, I don't think I'll ever get DH to stay there.
Other times the prioirty is being inexpensive.
AS far as amenities...That's though to answer, but I'd probably say the biggest jump for us is missing the amenities at the values. It almost doesn't make sense to me that the values don't have pool towels. We really missed the fridge, coffee maker (how can you have coffee without milk?). I don't eat much in the rooms, but being able to have a little food in the room is a big plus!
The moderates have nice room decor, all ofhte above, great pools....but the locations are about like teh values, the busing is often slow, the resorts are often BIG. I don't like losing so much time walking back and forth across the resort.
The room size isn't so much of a factor for us, generally - unless you have a room filled to capacity. If you've got a family of five - that extra space is worth more of a premium than with two people. (I've had trips of both). An extra vanity sink outsid ethe bathroom can be a real time saver. For others, having an extra room, and thus an extra bathroom, is a real plus.
I think there also a few intangibles - like having an easy escape route from your room (outside corriders) or having interior corridors in cold weather. The deluxes also allow you to customize your room view. How do you price the value of seeing giraffes or the MK castle from your room?
Finally, here's an intangible that's mostly either ignored or disputed on the DIS. I don't care what others say. There's at least an imagined class difference between the resorts. When you are GF, you know you are at the flagship resort. Some folks prefer the atmosphere of Pop, or the mods- and that's fine. That's part of the point - it's hard to price one's comfort level when it comes to class. Some folks can easily switch between any resort and some don't even notice any difference, others notice but don't care, some feel uncomfortable staying outside what they feel to be their own class level.