Pros
Interesting work, good SAP customizations, nice office, good opportunity to learn about financial analysis for tech, reasonable work hours, garage parking (great for winter), good pay.
Cons
Research the turnover rate at the Chicago office. There's a reason for it. Are you aware that US Cellular sold part of its customer base (Chicagoland) to Sprint in 2012-2013 and had to downsize its staff. US Cellular is facing tough competition from much larger industry players. The downsizing reminds me a bit of the TV series "Survivor", and likely had a similar impact on company culture. When a once growing company starts to decline.. and as the future becomes uncertain.. the impact on interpersonal relationships in an office can breed dysfunction.. Do your research when considering this option.