As someone who's been flying a lot more ASA than I would like to over the past 3 months, here are my views (as a small 5'6" guy):
Legroom is poor in all rows. The exit rows have about an extra .5 inches, but the padding is thinner. Seats are also a little narrower than on mainline planes in my experiences (I normally have a little wiggle room on a mainline plane, not so on the RJ
Snacks are the typical Delta lot. Regular drink service, plus a smaller snack basket (the last few times, it's been peanuts, granola bars, cheese and crackers, and maybe one more thing).
Storage space is tight. I have a reasonably large briefcase and it gets in under the seat, but does take away a little underseat storage space from my seatmate (there's a reason Medallions get Zone 1 boarding...get that space first!). Overhead space won't take much either.