I've made the switch 4 years ago and never looked back. I thought it'd be struggle to take the bike when (good) public transport is available (Berlin, Germany) but I've found that it doesn't require any willpower: I prefer the independence and that I get to see the city, and not just the subway walls. Anything within a 10km radius is absolutely no problem. During the day I'm faster than a car, and at night it's just…
I commute north-south, alongside S1 train. I noticed it recently got a lot harder though. It seems like there's construction work everywhere (even on the riverbanks and channels). I need to to add extra kilometres just to cut through Mitte.
Also my route is very "hilly", both ways (northern Mitte to Schöneberg). I guess going east-west may be a lot easier.
I have to agree though, cycling is usually faster than U-Bahns and buses. Trams are not even worth discussing. I still found S-Bahns to be the fastest.