Germans have a mode of interaction known as "business polite" (I forget what the actual term is in German) that some American travelers mistake for coldness. For example, if you're accustomed to wait staff pretending to be your life-long friend and stopping by every 10 minutes to ask if everything is OK, don't expect that in Germany (or most of Europe, actually). There's no pretense that the interaction between two parties who don't know each other is anything other than a business transaction. Respectful courtesy is maintained, but don't expect to meet your new besty (looking at you, Rick Steves fans...).
As someone who naturally is a bit more introverted, I vastly prefer the honesty of a business polite interaction to the shallow friendliness we do here.
I worked for a bank for 10 years in the US with a lot of German clients/employees, as well as traveling to Austria and Germany. I only speak English and completely agree with your "business polite" comments. I can always tell if someone is a native German, even when they only use English. Always nice and polite, but there's a difference from Americans (like most other cultures).
Most European countries take forever when it comes to table service. It's not because they are rude or don't care (well tips are less important, so they don't need to fawn over you), but it is usually due to less staffing. Since everyone is salary they hire fewer waiters and they need to cover more tables per person, so it takes longer. Good idea is to always get the check (and please make it clear if you are using credit card when you ask for it..show them the card as you do the "check wave"), as you are finishing your food...don't wait for the end, bc you could wait 20 minutes for it. Also, for Lunch, if you are sitting down with a waiter, you need about 2 hours before your next tour, etc.
We always do well when traveling to non-english speaking countries. We try to learn a decent amount of basic language, like to order food, pleasantries, directions, etc. Luckily we know some French and Italian, and basic German isn't hard. They almost always switch into English for us, but you can tell they appreciate the attempt. The service is always great. Avoid tourist traps, go off the beaten path for better food! We also try to blend in and not look like tourists as much as possible. No big cameras, no backpacks (use a plain black draw string bag w/o english words that blends into you), no baseball hats, etc. A little cultural research goes a long way as each country has a different dress code (unless you go to DLP, then wear anything you want).
