Badger, I know that - I spent a month in Germany and used public transportation all over the country. BUT when I first flew in, I hadn't been to Germany in 11 years and had never been to Berlin, I was exhausted after a long night of flying, a 7+ hour layover at CDG, and a fiasco when my AF flight to BER had to turn back to CDG mid-flight, then after an hour or so of scrambling around the airport, leave again. So by the time I got to BER, I hadn't slept in almost 18 hours (I can never sleep on planes), my brain was fried and it was dark outside. I didn't care how cheap and easy public transportation was - I just wanted to get to my hotel as quick and easy as I could.
I wanted to tell Heather this, so that if she is feeling that same way, she may want to consider the ease of just grabbing a taxi. In the general scheme of things, a €45 cab ride is small change compared to the entire cost of the trip and peace of mind. Heather may not have the same circumstances. She may be the kind of person that sleeps well on a flight and will be feeling rested when she gets there. But I just wanted to point out why I took the taxi and why it might be a good option.