I'll be honest - I chickened out and changed my reservation from Shades of Green to Coronado when the
Free Dining promotion was going on. I did not think the SoG dining plan was worth it - we would not want to trek back to the resort to eat dinner each night, and I didn't read very complimentary things here on the DIS about the meals there anyway. I also read at least one thread that said that the bus service was less than stellar (at some point this summer one bus was out of service and it made for long waits).
What I did was work out how much our vacation at SoG would cost, including an estimate for food. At my dh's rank, 6 nights would run $618, which I thought was great. Then, I started figuring meals. I had already booked character meals at Hollywood & Vine and Chef Mickey's, and dinner at Le Cellier. Even making allowances for eating some breakfasts in the room and skipping lunches if we ate the big breakfast at SoG buffet, I still came up with spending at least $500 on food/snacks, for a total of $1118, plus we'd have to spend $70 in parking fees. For the same total, I booked Coronado for the same length of stay and got the free dining promotion. We'll get more sit-down meals at our choice of places (including 2 more character meals) and have the counter-service meal each day. I thought it a better deal for us.
I'm sure we'll stay at SoG at some point in the future when our kids are older or if DH and I can manage to get away for a no-kids trip. Having little ones, I was less willing to be frustrated with the bus service.
Good luck with your decision!