for the atomosphere is it worth the extra money?
Absolutely.......ABSOLUTELY...........
ABSOLUTELY
Should I say that again?

.
IMHO, and I've debated this at length with many a person, PO Riverside is everything that a WDW resort experience should be, while the values are little more than a wonderful opportunity to stay in a nice hotel in the middle of WDW (not that that is chopped liver

).
Let me elaborate, and hopefully keep from getting flamed by those who love the values.
Disney has been, and always will be, about themeing. It's about experiences. It's about details. It's about options. These are all things that the moderates, and POR in particular, have in abundance over the values. Yes, the valuse are cheap. Yes, they have neat Disney based decorations (note I didn't say theme

), they have great food courts, and they are fun....but that's it, IMHO, not that that isn't a lot. We've stayed at the All Stars, and it has a lot to offer. The moderates just have so much more.
Take POR. The first thing that strikes you is the incredible themeing. You are taken back in time to the old south. The main building is just the start. You have the whole central port and marina area...very well done with the docks, the bridge, the water wheel, etc.. You can meander over to Old Man Island, where the pool is very interesting and fun to sit by.......perhaps relax and have a drink at the pool side bar. Then you can venture further. You can wander past the sprawling mansions of the old south, or adventure through the bayous and back woods. Take a pleasant stroll along the river, watch children fish, watch the boats go by....it's beautiful. And that's just the start. Don't feel like being by the main pool at Old Man Island? Take your pick of the beautiful quiet pools. Want a horse and buggy ride....go grab one for a reasonable $30 bucks or so. Want to head to DTD or PI...hop a boat for a pleasant ride. Rent a bike and explore the river down to POFQ. Maybe wear your bathing suit and try the pool over there, or just take in the atmosphere of New Orleans. Want a quick bite... the food court is great. In the mood for an adult sit down meal in a nice restaurant, you can do that too. There are just sooo many options, all adding to the incredible atmosphere and wonderful themeing. That is what Disney does best, and it's DEFINITELY worth $40 a nite more if you can swing it. To me, a stay at POR is an experience in and of itself, in addition to the experience of being in WDW and going to the parks. For me, the values are more of a gateway to the experience of being in WDW and going to the parks, but aren't necessarily a big experience of their own. Walking around them is interesting, what with the neat decorations and all, but it certainly doesn't provide you with everything that a resort like POR does.
Sure, the room at a moderate isn't that much better than the values, although it is larger. But it isn't the room that you are paying the extra for. Try POR and you won't be disappointed.