I live on the Peckham Rye side of East Dulwich, so have the option of trains to Blackfriars, Victoria or London Bridge. Buses arriving every few minutes take me to the station in 5 minutes. I work in the city and have a 35 minute door-to-door trip every morning. That's the same commute time as when I was living in Chelsea. I guarantee that trains are a whole lot more comfortable that tube trains, especially in the summer!