When we first started staying 'on site', we did only values. Twice. Worked out great for us, as our kids were under 6 yrs for both stays, so we didn't feel we needed or wanted any of the additional amenities that the mods and up had. The pool was fine for us, smaller rooms were okay. The food courts worked great because the kids were not big eaters, so we saved $$$ there.
On our last trip, the kids were older so we tried a mod (POR...Dixie Landings when we were there). The larger pool with the slide was a hit, bicycle rentals were great, better food choices, etc. all were great. We knew then we'd never go back to value.
After seeing the inside of the WL on that trip during a character breakfast at Artists Point, we knew we wanted to stay there next. As the most reasonably priced deluxe at the time, we thought we could afford it if we saved a little more. I honestly feel that once we get 'spoiled' with what is there, we won't want to go back to a moderate.
I guess the easiest way to put it is that the difference between a value and a moderate is the difference between a Best Western Motel and a Mariott. If a clean, comfortable room and a pool is all you really want, a value will be fine. If you're looking for a little more, then a moderate is really the way to go.