if you want more good pow days, chillan is definitely better because in the resorts near santiago the snow gets fucked up with the wind and there are no trees so it sucks on cloudy days.
the "tourist trap" its only on valle, la parva, el colorado and farellones are not like that,
and the terrain is as steep as in chillan and its really good with the right conditions , you just need to hike a little bit (
https://vimeo.com/112763254 for example that are some spots in la parva that are not "too flat")
chillan is still a really good option but not for skiing park