I grew up in NB and also lived there (rented) as an adult. I live in a neighboring town and frequent NB businesses by choice/preference.

NB as a town has been slowly improving and continues to improve, but in my experience, the rent ceiling will be low in relation to neighboring towns. I won't comment on specific rents as my info would be a little out of date, but historically, you can get a lot of bang for your buck (as a renter).

Schools are dismal, mostly NBHS, but the lower schools aren't great either.

East Street/North Street areas are bad. Downtown has some shenanigans but has been steadily improving. The CCSU area and the West End are the nicer parts of town.

Restaurants and a couple of breweries bring in a lot of outside visitors. There is a vibrant Polish district with a ton of grocery stores and services for the Polish-American community. There are also some really good Puerto Rican restaurants as well as a couple of Middle Eastern joints in addition to the usual staples.

CCSU area is great for an income-generating property (college students), but the barrier to entry will be tougher than elsewhere in town.

My advice would be to spend some time and money in town and see for yourself.