Yes 38 can have high loading, but SBST treats it as an
alternative to 12 and 229. I had written earlier to SBST on 38 to
add bus as frequency can be 15-18 mins in peak hours and worse in
off-peak and reply was that I could also use 12, 20 and 229.
From what I observed, 38's loading from Simei Rd (near PIE) is
generally more than 20's. About half of them alight at Tampines
East CC while the rest continue their way to Tampines Int. (At
least this is what happened when I joyrided 38 last time from Simei
to Tampines)