I moved here from London, and I'd say it's a nice change of pace; live is pretty relaxed here.
It depends on what you're after, but I think there's something for everyone. Many young people come here for the usual Berlin lifestyle, partying all the time (it helps that the cost of living is relatively low), but aside from that, there's a lot going on generally.
English is very common, but I would recommend trying your best in German. I'm rubbish currently, but we'll get there.
It's pretty cold right now (hovering around 0 to 5°C), but it gets to the low 30s in summer, so I'm sure you won't mind that when you go!
I think Berlin actually fares quite well for biotech, though perhaps language would be more of an issue. See how you go!