Advice on a place to live

I am commuting to Cannot Street Station for work. Currently, I am looking for flatshares such are options:

• Mile End - take district or central lines either to Bank or Cannot Street. Theoretically, up to 25 mins commute door to door.
• Bermondsey - take a bus or get on Southern train. Commute is 35 mins AND the place is 100 GBP more expensive per month.
• Stepney Green area, near tube. The only viable option is District line.

Can people comment on reliability of Central, District lines? Are they very crowded? How about the area of Mile End, Stepney Green or Bermondsey? I also will update the thread if I find something else interesting.