Even these days, Nashua is fairly typical of old New England mill towns that have gentrified to some degree. This mostly translates into having maybe a couple dozen square blocks of nice restaurants and shops in a walkable downtown but things get pretty rundown and/or strip-mallish as soon as you get beyond that area.

I'm not sure how much a train would even help. In my experience, having worked with many such folks over the years, many of those commuting down from NH are headed to employers in tech and elsewhere scattered all over the greater Boston area.