I've spend a lot of time in Berlin, and I find it hard to read. Mostly in that sometimes it's relatively annoying to determine what lines will get me from Station A to Station B.

For example, let's say you're a tourist and you arrive at Hauptbahnhof, and you need to get to get to Alexanderplatz - what lines will get you there?

There's a whole bunch, and it's very hard to figure that out quickly. Or you might see that the S9 does what you need and you'll just wait for that, so you'll go there and wait, while the S3,S5,S7 pass you by.