Ted Templeman, their longtime producer and man behind all of those albums sounding sound good talks a lot about the influence of Michael McDonald, who essentially saved the band, in his (worth reading) autobiography. With Tom Johnson out for health reasons, they were somewhat spinning their wheels until McDonald came in and wrote some enormous hits for them that put them back on the charts.
It is essentially two different bands, pre and post McDonald. I like both versions a lot, but prefer the biker-esque vibe their earlier albums had. As far as band members and lineup, I prefer any that had Tiran Porter on bass, who had as much to do with their sound as anything. His bass lines were always infectious and interesting. I’ve never thought that the band sounded nearly as good without him.
And yeah, Another Park, Another Sunday is a masterful tune, as is South City Midnight Lady, The Captain and Me, and Black Water. I mean, China Grove and Long Train Running are great rockers, but I prefer their more melodic stuff.