Pros
Thermo services many different industries by providing everything for a laboratory from real estate services to instruments to the trash can under the bench. This variety can be a huge benefit because your exposure to so many industries gives you valuable experience that you can apply almost anywhere within the company or even if you leave the company.
Cons
Thermo was formed as a series of acquisitions, many of which have not ever bee integrated. There is a lot of isolation between divisions so it can be hard to move around the company or even get information about our own products. If you are ambitious in your career, you will want to make it happen for yourself. Thermo will not do the work for you. But then, if you are content to wait while someone else helps you, you probably won't get too far in your career anyway.