I took a taxi to/from work in Beijing even though I eventually lived on line 10 which would do much of the same route (well, a bit more walking in the work side). I shifted my work schedule to really early to do it, and I think it was worth it. The subway is slow, has annoying security to line up for at the stations, and you often don’t get a seat for most of or your entire ride. I tried it a couple of times and it just wasn’t worth it unless I needed to travel during rush hour.

I’m sure if it were Tokyo instead I wouldn’t have a problem (or even the option given the higher cost of taking a taxi).