Yes you should move to Berlin if you have the chance to get permanent residency or even the citizenship. If you live in Germany, you live in Europe and can relocate to another country within the EU easily. The German citizenship is THE most valuable in the world ( http://www.telegraph.co.uk/travel/lists/most-powerful-passpo... ). The German economy is one of the strongest in the world. You'll live in a free, welcoming and open democracy. I wouldn't care so much about the perks, but about the fact that you're in the EU, and specifically in Germany.
ps: If you got so far to get a job offer with relocation in Germany, you'll also easily find another job here. Maybe not in Berlin, but Munich for example has all the big names: Google, Microsoft, IBM, Autodesk, Salesforce, (the list goes on and is really long).