Yester-day, I figured out some parts in Colin Blunstone's "Planes" (a synth phrase and some of the chords), after which I decided to listen to the Planes/Never Even Thought two-albums-on-one-CD reissue. I noticed a few small things.
In "Only with You," "down" in the lines "Before love had always had / Its ups and downs" is sung with a descending melisma (C# B A), musically reflecting the word's meaning.
I referenced the Beach Boys' original (on Holland), and while it also has this feature, it's less pronounced; it's sung to just two notes (B# G#, I think).