Obviously this won't be happening anytime within the next 18 - 24 months, if not beyond. With Express service to just Makkasan on 60 minute headways, a lot fewer people will be riding the Express line. Most seem to think you'd need 15 - 20 minute headways, with a single Express service stopping at both Makkasan and Phaya Thai to have any reasonable chance of breaking even. However, until the track is reworked this is not feasible. Maybe in four or five years - once they have more rolling stock, and have reworked the tracks - the Express service will be a viaable option?

The City Line is great for commuters to/from the eastern suburbs, and ridership figures tend to peak during special events like protests, concerts and other special events in the city, or at Ramkhamhaeng. It is probably helpful for airport employees as well.

Not sure what the percentage of passengers is for people actually flying into/out of SBIA, but suspect it's fairly small?

I assume the concept ( airline/baggage check-in, spend time in the city, fast, comfortable trips to/from the airport ) of the City Air Terminal at Makkasan remains a pipe-dream for the foreseeable future? The amount of space going to waste there is amazing, save for the few TV shows/commercials which occasionally get filmed there.

Given all the problems, issues and financial losses the SARL does look like a losing proposition if analyzed in a vacuum, but any improvements in public transportation probably benefit the city, assuming fares remain subsidized and the huge losses can continue to be absorbed.