Pros
Nationwide is an enormous organization, meaning that there are a wide variety of opportunities at their large-campus locations. A tremendous amount of effort is expended to maintain a positive company image as well as foster enthusiasm in their ranks. Wages are great, 401(k) contribution is good, and, unlike many companies, there is also a pension program.
Cons
There's nothing wrong with an organization speaking highly of their own successes, values, etc., but this company seems almost a little bit too in love with itself, which can lead to arrogance in decision-making and an immunity to constructive feedback. Meetings with upper leadership quickly devolve into un-constructive "kiss-up" sessions. This is fine for the most part: a large national carrier like Nationwide, Geico, States All- & Farm, etc. can make money hand over fist in direct sales while running on auto pilot as quantity beats quality. This breezy attitude, unfortunately, does not fly in the independent agent market that Nationwide is attempting to infiltrate (in part, by purchasing regional carriers- which is how I became a NW employee). All the witty TV commercials and treacly appeals to company values mean nothing to agents when service suffers due to closing offices and the resulting attrition of staff and talent. Additionally, going back to the "Pro" about compensation, if you have health problems, expect the "great" wages to be spent on out-of-pocket medical expenses as NW, probably like many companies now, only offer what is essentially the bare-minimal product that can legally be called "health insurance".