I thought his speech was disappointing. He played it very safe. What he said was insubstantial even by his standards, and sometimes painfully banal. And it seemed to me to lack the flair in delivery that usually makes up the deficit. There were no memorable lines. All that stuff about tearing down (metaphorical) walls was predictable and lame. It was a mistake to evoke memories of "Tear down this wall," an unrepeatably dramatic stroke. And who thought it was a good idea to recycle "This is the moment"? Old hat by now in the US and entirely without resonance in Germany. He seemed subdued and a little nervous, too, which would be understandable, since it is difficult to please two such different audiences--the one in Berlin, and the one back home--at the same time.
Speaking at home, a favorite device is to challenge his listeners a little (as recently, when he reminded a teachers' union that he supports merit pay and charter schools). There was a smidgen of that in Berlin--he called on Europe to increase its support for US efforts in Afghanistan--but no more, most likely because he did not know the audience well enough to be confident about getting the balance right.
For what it's worth, Der Spiegel was none too impressed.