The moderates are all essentially the same in terms of the services and amenities they offer, so it pretty much boils down to themeing.
Coronado Springs Resort(CSR) has a Mexican/Southwestern theme. It is adobe in appearance, very beautiful at night with the way they do the lighting. They have a nice pool area with a water slide...the area is themed like a Mayan temple archaeological site. There are also a couple of quiet pools scattered throughout the resort. One thing that I consider a drawback(although not a deal-breaker)is that the only hot tub is at the main pool...there are no hot tubs at the quiet pools. Now, it is a big hot tub, but sometimes you just don't feel like schlepping all the way to the main pool (which can be pretty far, depending on your location within the resort) if you want to use the hot tub. They have a very nice sit-down restaurant (The Mayan Grill) which offers a nice breakfast buffet. They have a food court (The Pepper Market) which is nice too. The one thing I don't care for about the Pepper Market is that it is a modified food court of sorts. You are seated and a server brings you drinks and "checks" on you, and for this they add 10% to your bill. But you still go around to all the food stations yourself to get your food, bring your little ticket which gets stamped with what you have purchased, and you pay on the way out. I'd rather get my drinks myself and not pay the extra 10%. We have stayed there a few times, and do find it overall to be a lovely resort. It is a convention center as well, so if you are there when a convention is there, it can be busy.
Port Orleans French Quarter (POFQ) is themed like the French Quarter of New Orleans. It is cute and quaint, with a nice pool area and a regular, serve yourself food court. There used to be a sit-down restaurant as well, but I am not sure if it is still there. There is also a bar where there is a piano player sometimes. It is the smallest in terms of area of allthe WDW moderates, pretty compact overall in terms of the distances you have to walk around the resort to get to the different areas of the resort. It has a cute little boat that takes you to Downtown Disney (DTD). The pool is cute...has sort of a Mardi Gras theme, with a slide that looks like a big dragon and you slide down his tongue. Last time we stayed there with our firends, they had their 7 year old along and she loved the pool!!!!!
Port Orleans Riverside (POR) used to be called Dixie Landings till they changed the name, which I never understaood why they changed the name, but nayhow... it is a cute resort as well. More spread out than POFQ. There are 2 sections to POR...Alligator Bayou and Magnolia Bend. Alligator Bayou is a more rustic feel...sort of what you expect in a Southern bayou atmosphere. Theres beautiful foliage, it's very lush and peaceful. Magnolia Bend is themed like the Southern planatations. Very pretty, butmore of an "open" feel, not as lush. Has a food court and I am not sure about a sit-down restaurant. Also has the boat to go to DTD. They have a regular food court and I am not site about a sit-down restaurant. POFQ & POR are sort of "sister" restaurants.
Carribbean Beach has a Carribbean, island theme. I haven't stayed there in a number of years, and it's been recently redone, so I can't speak much to it other than to stay that it is very spread out in terms of physical layout and if you are in one of the more distant buildings, it can be a long walk to the main area so keep that in mind with room requests if anyone has difficulty walking. We are actually thinking of booking there for a January 2006 trip, but are waiting a bit for some rates to come out.
You realy can't go wrong at any of them. It really does boil down to what theme you think you'd like best.