I can't explain it better than that
Down Down sounds to me smoother and less angular than
Let There Be Rock ...It's how I hear music,
Highway Star sounds to me sleek and elegant,
Immigrant Song heavy-handed.
It's where our music tastes differ, Rob, I always gravitate towards a certain fluidity in music (which I think you find a little banal) and you appreciate rhythmic accentuation which to me sometimes sounds jagged. That is actually a word I was looking for: AC/DC (there, I said it!) sounds jagged to me, so does much of Led Zeppelin, always has. Your music taste has a stronger black component than mine, it's where your love for Mothers Finest stems from and it showed up in your (very good) playing in Superfloor too.
You once said that Jim Lea's bass playing in
How Does It Feel does nothing for you, neither his (Dave Hill mimes his parts below, Jim is at the piano) melodic parts at the beginning, nor his walking bass in the middle parts - yet I adore what he does, it has a melodic flow to me. I guess I'm only a cello player at heart and you're the real bassist!
Those melodic "lead bass" parts Jim has sprinkled so liberally over this song make me cream in my pants.