Rode the subway a couple of times last week and it works like a charm. ^ All rides only 10 baht from anywhere to anywhere too until August 12, the Queen's Birthday... after which rides may cost up to 32 baht (still less than $1).

Ticket vending machines are mostly not installed yet though, so you'll have to queue up at the counters, and the concept of tapping the token to get into the subway is continuing to confuse the joyriders so expect some crowds at rush hour.