I'm not positive, but I think Woodridge is one of the new smaller Imax theaters. If you want to take full advantage of "The Imax Experience," then the place to go in Chi-town is Navy Pier. They have the biggest screen by far. Of course, they also have the highest prices, and they sell out quickly, and you have to pay extraordinary amounts for parking, but such is life.
Also, I'm a projectionist who has dealt with the new digital 3D stuff since the very beginning, and I've seen every format that's out there except for the new digital Imax stuff. I honestly have to say that despite the numbers, digital 3D looks better than traditional Imax 3D. The reason for this is a number of factors which naturally occur in an imperfect environment.
With Imax 3D, you start out with the disadvantage of the 3D system, which as David said, is inferior by nature. There is substantially more ghosting than there is in the digital systems. I think that the reason for this is because Imax uses linear polarization as opposed to circular polarization, but don't quote me on that.
But then on top of that, Imax uses two prints on two projectors running in unison. So if there are imperfections on one but not the other, things will look weird in just one eye. Even though Imax will most certainly be brighter, the two eyes might not be evenly bright, one eye might be slightly out of focus, one eye might jitter, etc.
And then you have the problem of dirt, which has plague every Imax presentation I've ever seen. As I understand it, Imax projectors have a piece of glass known as a "field flattener" which picks up dust like crazy. You see this big blob in the center of the frame, and it'll slowly move across the entire screen. It's very annoying.
To me, the three big advantages to Imax are size, brightness, and resolution. But for most movies, you can get rid of resolution, because they're usually not mastered at anything higher than 2K. I'm guessing that this is the case with A CHRISTMAS CAROL, but I'm not sure. So that leaves size and brightness. Like Josh said, most of these screens are not that big, so that leaves brightness.
If it were me, I'd go with a digital presentation, because the 3D is so much better. I know that's not the popular opinion, and a lot of factors have to do with each individual venue, but that would be my recommendation.