Spirit’s website also has a full playlist page, which can be seen here: http://www.spiritradio.com.au/listen/
Their positioner is “Classic Rock & Today’s Hits”, and from briefly looking at the playlist on the link above, it’s not hard to see that it has a favourable rock skew to it. In the Bunbury market, it’s a good alternative to Triple M’s “Classic Hits” format, so they have a pretty good selection of adult commercial music stations there, both of which are on the AM band. Both Spirit & Triple M in Bunbury should convert to FM, given that analogue TV services on VHF 3 & 5 have switched off, but are not eligible for a AM-FM conversion, given that it’s not a solus market (Mandurah is eligible, meaning that 6MM can convert to FM).
I think that Spirit Radio would probably be the best adult commercial music station in all of WA. 