I may be a little late chiming in here, but we just returned from the Contemporary NGW through Shades of Green, and if I was in your shoes, I would DEFINITELY choose the WL instead.
Don't get me wrong, for the price we paid at the Contemporary ($78/night) I certainly can't complain, but if there was only a $156 price difference between the two resorts, it would be no contest for me. I didn't like the theming at the Contemporary at all. It just didn't seem "vacation-y" to me. I agree with the OP who described it as an "airport" feel, although I would have gone with hospital waiting room! LOL
The rooms at the CR were clean and roomy, but the garden wings are definitely showing a LOT of wear and tear and are in bad need of a rehab. There are scuff marks everywhere on the walls in the hallway, and lots of peeling wallpaper. It's not at all dirty, just seems a little run down. Our cabinet door fell off several times, and we were missing knobs on the bathroom vanity. All this I could overlook for the great rate we received, but if I had paid any more than we did, I would have certainly asked to be moved to another resort.
It was nice staying at a monorail resort, but the monorail was actually quite a hike from our room. We also didn't like being in a separate building from the main lobby, shops, etc.
We visited the WL for dinner during our trip, and were really disappointed that we weren't staying there instead. The next time around, if Shades of Green isn't available, we'll definitely spend the extra money to stay at the WL. We just felt like we missed too much in theming this time around.
Hope this doesn't sound too negative, we didn't hate the CR, but we don't think we'd return again.
Have fun no matter what you decide!
Jynohn