Vantaggi
Nokia is a HUGE company, so it is critical to understand where you're going (will you be a part of Business Unit, Regional staff, Admin function that reports to Finland, etc.). Your experience will vary a Lot depending on where you work. I'm only familiar with a part of Nokia that develops networking equipment. The culture of this group is very different from the rest of the company. The group originally was formed by f-Alcatel purchase of a Silicon Valley start-up, so many people has done one+ start-ups and consequently the culture reflects it.
Svantaggi
It's important to read Pros. Cons - you are a part of a very large company. If you're a superstar, it might not hurt you, but if you're "just a great above expectations employee", you might face with the fact that in order to increase xxx (whatever you want to increase), you'll have to look elsewhere. The pros - your paycheck comes regularly. The cons - it is hard to get anything special related to compensation because if your business/your role is doing great, there is certainly another business within such large company that is doing poorly. No stock (technically there is stock, but ... $5-stock with no stock grants is the same as "no stock)