I've never stayed at the Contemporary, but I've visited it many times.
It isn't the prettiest of buildings from the outside, but it does have several advantages over the other resorts.
The first is the location. As you said, it's on the monorail and is only a few minutes walk from the MK.
If you are lucky enough to have a tower room facing the MK, the views are second to none.
The California Grill is another big plus. One of the finest Disney restaurants, it also has possibly the finest view in all of WDW. If you time it right you can get a window seat and watch Wishes and Reflections of Earth on the same evening.
The pools are very nice and are situated by the side of Bay Lake.
I'm sure you won't consider it a mistake when you arrive!
Kev