Pros
Thermo Fisher really encourages managers to develop their employees into larger contributors, leaders, functional experts, etc. If you're committed to the company, but not really sure where the right fit is, you can openly seek a new role elsewhere and your manager will most likely support it.
Cons
The downside to the growth is that you will most likely have to relocate. If you're open to it, you can bounce around the world. But unless you're in one of the major footprint areas for the company (Waltham, MA; Pittsburgh, PA; or now Carlsbad, CA (formerly Life Technologies HQ)), then that next opportunity means packing your bags. Some people love it, others feel trapped - you typically commit to a couple years in the new location in return for relo assistance, but then you're likely to be asked to move again, once you're seen as a 'team player.' There can be a fair amount of pressure on relocation.