I am a native German, and have spent about 15 years in different foreign countries (USA, France, Spain, Switzerland, China and others).
I am still surprised to see what image Germany has in different parts of the world, compared to how I see Germany myself. I think the explanation is that Germany has changed a lot over time. Certainly the most decisive event was WW2, or even more so the Nazi regime's rise to power and abuse of that power.
Unlike other countries which had serious misconduct of their own in the past, Germany has a unique willingness to never forget what happened, why it was possible, and what it takes to make it impossible for history to repeat itself.
In the US, hardly anybody talks about the fate of the native Americans. The Japanese worship war criminals. The Spanish act as if the Franco dictatorship had never happened, in France, you could believe that everybody was in the resistance against the Nazis etc.
I think it is this mindset which allowed Germany to recover from the world's bad guy to a nation which has one of the best passports you can own in terms of ease of entry, visa requirements etc. to other foreign countries (together with Canada, Switzerland and Sweden).
At the same time, it changed the Germans quite a bit. It is believed that their skepticism towards new technologies has to do with the fact how the Nazis abused technology for waging war. Germans are also very sensitive about state authority, e.g. when it comes to protecting their personal data, to keep it private. This goes so far that most Germans are against fingerprints in the passport, although a passport is a means of identification, and the fingerprint is a unique identifier.
Many of the positive German qualities are less visible today than in the past. Punctuality I find in CRH, not in German railways (not at all, actually). Hard working is also not really true anymore, if you consider widespread 35h work weeks, unions now clamoring for 28h.
On the other hand, Germans are very efficient during their active hours. They use their own head to solve new problems, instead of relying on knowledge learnt by heart.
They can be precise to the point of being painful. This can be terrible when discussing nitty gritty issues, but it is the key to perfectioning products. They develop a patience in this respect which fast evolving countries typically don't have.
As some others have rightfully pointed out: There are never "THE" Germans, or "THE" Chinese. But on average, I think it is fair to say that some of the typical Germany qualities can still be found, while others have changed quite a bit.