The STs are 520W and it's assumed the touring bikes will have heated gear and various gizmos. I.E. 520 should be sufficient to handle the typical sport tourer's needs. Compare, however, this to some of the 'touring' bikes w.about 1000W and you see a huge difference.
My '96 916 has the anemic 325W stator output and somehow I run 99W of heated gear with no problems. Because of the R/R vulnerability I do worry, and in fact won't run the gear full steam while my brights, indicator, and brake lights are on. I have no issues running the gear otherwise. Oh yeah, I run my GPS too with the gear on.
In contrast, My 92 SS also has the 325W output and I can't run my heated gear while running around town, without having to roll start it towards the end of the day. It largely depends on how much time I'm idling at lights (here in NYC that can be signifcant amt of time

), but I usually shut the heat at stops or keep idle to 3K.
480 is a good # for a superbike IMO. Enables guys like me who rip it up at tracks and want the ability to run some extras on the street.