Doesn't VZW work the best overall in and around Chicago? There really only seems to be a select few places in this country where at&t works better than VZW with overall reception.
In your current scenario, I think it's worth it to switch providers to get the Note. It's simply that great of a device. Although it seems like many current Sprint-ers are holding out hope that Sprint will get it too.
Back in June 2010 when my at&t contract expired, I came awefully close to switching to Sprint just for the EVO. But then I had enough people talk me out of it...citing the slow data speeds and rather spotty reception (esp indoors).
[iPhone 2G, 3G, 3GS, 4]; Aria, Desire HD, Focus, Captivate, Atrix, Streak, Titan, Venue Pro, GS2 (EUR), HP Pre 3, G Nexus (EUR), AT&T Galaxy Note I717