I'd do the BOS swap. It will work fine. ORD has dozens of openings so as soon as you ask to switch to it, you'll get it.

The CRJ is more like the XNA shuttle. Add in about 8 other destinations and that's all you do. EVER. Also, ORD in the CRJ has very few lines. For example, a buddy with roughly 3 years seniority on the CRJ could barely hold a line, then switched to DFW where he can easily hold a line with weekends off.

If I were you and knowing what I know now, I would without a doubt ask for BOS or LGA and get the ERJ for certain and switch later.