I have lived in Portage for the last two years. I relocated here a few years after college from the suburbs of Detroit and own a home here. I would say it is similar here to other suburbs, and would be an especially easy transition for anyone moving from the suburban Detroit or Grand Rapids areas. The close access to Kalamazoo and everything available there is great. The affordability factor is also a serious draw to living in Portage. It is definitely a commute friendly distance from Kalamazoo. It is only fifteen to twenty minutes if you live closer to the city.
Living in Portage is not a mile-a-minute level of excitement like living in a big city and activities are somewhat limited. In the summer there is great swimming in the nearby lakes (check out Ramona Park Beach), and there are quite a few beautiful parks with extensive trails. A person who loves to walk or ride their bike would really enjoy it, and if you go, try starting out at Celery park. There are also the usual stores in the area that you find through the rest of Michigan (Meijer, ect), and the average chain restaurants. For specialty food or drink (like a microbrewery), definitely venture into Kalamazoo.
There is a really neat little museum I take my visiting family to called the Air Zoo. It's an aerospace park with rides, but also has exhibits that describe air travel and flight history. My siblings all have children now so I wanted to take them somewhere they could run a little bit on a rainy day. They had a great time on the hot air balloon ‘teacup' style ride. It's not a huge place, but definitely worth a visit, especially if you have kids!