Life-long 40 yr Gadsden resident/visitor here....Southside is the trendy place to now live in the area. "living on the mountain" used to be, but is no more, although I personally love noccalula and intend to move up there some day. Bayou is right--there are parts of EAst Gadsden/Glencoe that leave a lot to be desired, but the whole area is not that bad.
As far as restaurants go, Top of the River is great--great atmosphere and good country food and catfish. Unfortunately, outside of that, chain restaurants are about all you have. IMO, Pruitts, all the BBQ restaurants including Dad's and Uncle Sam's, are all OVER RATED. Beans and Greens in Hokes Bluff/BallPlay is decent, and there is diner called the West Gadsden Cafe downtown that is pretty good if you like a meat and three type lunch. The mall leaves much to be desired, although there is some renovation going on right now with the JC Penney addition. Ruby Tuesdays is pricy, but the food is decent for a chain restaurant. If you like Mexican, El Tapatio is really good. They have a location on both the river and in RBC. Also, as Bama Law pointed out, Maters downtown has a great rep as italian restaurant/pizzaria, although somehow I have never made it over there to personally try it.