I'm a huge fan...and for good reason.
Pros
I've worked with Unum almost 8 years in 2 different depts. and several different roles. I love it here and (as of today) hope to be a lifer. There is an excellent culture, community involvement, encouragement to volunteer, focus on personal development, outstanding benefits, focus on continuous improvement, and we provide an excellent product. I started at the very bottom as a call center rep and have worked my way into management in an operational area. I was given opportunities to prove myself, received valuable input and feedback to assist in my development, and rewarded for doing a good job. As with anywhere, there are always those with a grass-is-greener mentality. There are always complainers (I've seen some of them here), but they would complain no matter what company they work for. We see many of them leave Unum, only to return months or years later when they realize how good Unum actually is. I'm sure I sound like a company fanboy...and I am. But it's only because of how good the company has been to me.
Cons
Too conservative in business strategy, need to take more calculated risks and act faster on them. While I don't want to see a swing too far in the opposite direction, in a fast-paced world Unum often takes too long to bring a new product or service to market. Need to be more proactive rather than reactive to the market.