+ Accuracy & Reliability
While the subway takes about 25mins from Wudaokou to Qianmen, the bus may take 1 hr or more during peak hrs.

+ Cheap
Regardless of distance/stops, the train fare is 2RMB. Cab from Wudaokou to Pingguoyuan (extreme left on the red line) costs 15RMB which is more than 7 times the cost of taking the subway!

Despite its accuracy and cheap fare, I dun like to take the subway.

- Transfer
I stay at Wudaokou which is on the yellow-orange line. In order to reach Wangfujing (red line), I need to transfer twice at Xizhimen (blue line) and Fuxingmen. Sounds like going to harborfront from gombak? Wrong! In order to transfer, I need to walk the equivalent distance of sg's citylink mall from cityhall mrt to suntec city. So it means I need to walk citylink twice la! Can u imagine after walking the whole day in huge imperial gardens and palaces plus boat peddaling, still need to squeeze mrt and walk citylink twice! Some more all stairs la! And then still need to cycle back to hostel! Shag la!

- No air-con
Different lines are run by different companies. Some trains have air-con, some dun have. If u happen to stand under the fan then gd for u. If not, with a train packed with people plus a few layers of thick clothes on ur body, it's damn HOT la!

- Not convenient
Some places of interest are not located beside/near the subway. U might have to take another bus or walk some distance. Their "walk some distance" (like 15mins) can be damn far esp when u'r already very tired and ur feet are all sore from walking the whole day.

- Congestion
The situation is equally bad as sg.

Lastly, I can't hitch a free ride on the subway.