Can't tell you whether it's "worth it", but my experiences at the GF's RPC have been wonderful.
Yes, they will take care of all your ps's, entertainment requests, recreation, transportation, pre-arrival park shopping, assistance with special occassions or special requests. Upon arrival, your met by a concierge staff member and escorted upstairs for a private check in. You have the added benefit of being on a secure floor, with CM's on duty from 7am-10pm to assist with any last minute items you might have. A group of rooms does have an incredible view of Wishes each night and if you are more tied down to your room because of naps or early bed time, you can get a snack and glass of wine or beer from the lounge and enjoy it on your balcony. I've seen some parents who bring along a baby monitor and are able to relax in the lounge, with their children sleeping just a short distance away. Rooms on the 4th floor, with a lagoon view of the Poly and Epcot are viewable from the lounge.
The GF does offer room service, complete with crystal, china and heavy silverware. It's beautiful in itself and my youngest DD doesn't feel like we're on vacation until she can have a grilled cheese sandwich delivered. With concierge, you can also take that a step further and have private dining serve you and DH a romantic meal on your balcony while the kids sleep, or even just arrange a beautiful dessert and champagne.
Food offerings are nice and you can pretty much plan on being full from their deluxe continental breakfast. Cold drinks, coffee and tea are out all day long. Food tends to be a bit more gourmet, but they do have cookies with afternoon tea and in the evening, it's mini hot dogs and cupcakes for the kids. Late night desserts include some nice pastries, chocolate covered strawberries and cordials like Baileys and Kahlua.
It's really a higher level of service that you receive. The rooms do come with automatic turn down, robes and newspapers in the morning, but you can request these items with any standard room also.
If you do decide to go with a standard, garden view, I think SagoCay is a great building, especially with little ones. You're very convenient to the bus and monorail. If you have the back of the building, you'll actually see the monorail go by, which can be exciting for the kids, or you can request marina view and watch the ducks.
Hope that helps a little bit,
Tammi