Pros
My job was with a new business unit, created by a mix of companies in that sector that were bought and new hires. I was one of the new hires. It was an exciting proyect because you have half (or full) country to provide service. Never had issues with HR. Salaries were slightly over the industry median, and it was a "forward looking area". Other areas always complained of low salaries
Cons
Company culture is complicated, as there are several "tectonic layers" (the old, state-owned telco, the new management with sprinkles of european administration, each company that was integrated, etc.) You never get to know any strategic plans, which means that each change in direction is stressful. Very little regard for old-time employees, were the key to many company aspects were deposited. The is a large gap in culture, attitude and benefits between workers + mid-level management and top management.