Yup. Not that bad unless it's cold, raining or the DL and NW flights arrive at the same time. AA allegedly hates this, but YYZ won't accommodate them with jetways for the RJ's. The BOS flights (and now some LGA flights) were never part of AA's original plan at T3, which did not include any RJ's.

On the upside, I've never had a bad flight on this route - the onboard service has been better than average (for Eagle). Enjoy your visit to Toronto.