My experience with Berlin is 1) plenty of enthusiastic people and startups, 2) not enough funding to go around, 3) still some weird hiring practices in place. I have several decades of development+startup experience, and while interviewing for a CTO spot recently, I was asked in all seriousness what my GPA was. I could only guess, I hadn't thought about it in many years. The interviewer gravely informed me that most of their hires were in the "top 5%" of their graduating classes. This was a company that was allegedly, by their advertisements and verbal communications, looking for a tech cofounder/CTO.

I read recently online that Berlin is welcoming superstar American techies with open arms, which, of course, would be true of pretty much any startup community. I'm not surprised that they rolled out the red carpet for the author, but I don't think that ordinary non-German devs should expect the same or even similar treatment.

English-only speakers will find that one can get by just fine in Berlin without German. It's nice if you have a bit of it to facilitate communication with non-university-educated people, but it's just a nice-to-have. My experience is that people in the startup world here are incredibly fluent in English.

I love Berlin and look forward to returning, but the hype is pretty over-the-top. It's a good scene, but I don't think it's a great scene. Certainly nothing like SV or NYC. My purely subjective impression is that it's something more along the lines of a Toronto or perhaps a Boulder or an Austin.