Vantaggi
Sterling Commerce has become a big organization, and different parts of the organization have different work cultures.
I worked for one of the companies that Sterling acquired, and can only provide information regarding that group.
The best reason to work for Sterling Commerce is that it provides you a good exposure to the enterprise applications space. While Sterling apps are not at the level of an Oracle or SAP as far as customer base is concerned, it is still an interesting space, and it can be a good learning experience for a few years.
Svantaggi
As with a lot of large companies that grew by acquisitions, there is a risk of getting a group of products and companies that have relatively low compatibility and synergy, and can also be a difficult mix of company cultures.
The biggest downside of working at Sterling Commerce is common to a lot of companies - i.e. you have to manage your growth and career yourself, and it is best to look for other opportunities if you do not get growth within the company.