Pros
Mostly good people, overall good benefits, lots of challenging projects that are consumer facing to millions of customers.
Cons
Its a large enterprise, so by the senior management level you are definitely treated like a number. Lots of corporate mandatory training that is basically useless time waster. Also in a salaried position you are considered management and have to take classes every few years to cover unionized worker jobs in case of a strike (and potentially have to called up to cover during a strike). Health care coverage benefit was eroding over the years with cost being shifted more and more to the employee. You might think stability/job security would be a "pro" for a large telco company, but there are seismic shifts going on in the business sector and lots of "surplussing" (layoffs) happening all over the organization and lots of re-organizational churn. Recent reversal of telecommuting policies.