While Londonderry is a nice town now, be aware there are some big plans coming that could change that dramatically. For example looky here:
https://www.dpz.com/Projects/1006
and here
http://www.newhampshire.com/article/...WS02/151219767
I also heard that NH in the interest of trying to woo Amazon to build their east coast HQ here was eyeballing Londonderry.
Projects like this have a way of changing that small town feel permanently.
Also the proposed light rail running from Boston to Concord NH likely will put a lot of development pressure up and down the 93 corridor and probably if approved will create a boom of development in So NH.