I would tend to agree with this, since on the Chicago locals SD package, you get about DOUBLE the number of locals than you do with St.Louis, including 3 PBS choices. They also have ME-TV, which is like TV Land, only better & you also get the REAL WGN "local/CW" feed.
You can check for signal on x-ponder 31, 110 & this will tell you if you can receive those Chicago SD's.
I know you are asking for HD, but hey, why not get a little something extra for your trouble...