Hamburg is way better than Berlin, but Frankfort is even better than Hamburg IMO. The commercial area along the river, known to locals as "Mainhatten" (river Main, geddit!) is about as solid a spot in Europe as you can find for good commercial at the high end.
Good opportunities around this area generally. If you are just generally interested in Germany and not specifically in Hamburg, PM me and I'll give you the number of a guy who has good contacts there. I used to have a good contact in St Pauli area of Hamburg but he is now RIP unfortunately.