I'm always piddling around with gear changes just to see what seems to work for me.

One problem I've found with the contemporary compact setup -- 50/34 or something similar, with 11 or 12 tooth small cog to compensate -- is that at least with my bikes and gear, I can feel some odd vibration and resistance. Some tech-minded folks attribute this to chordal action. Apparently combining some chains with tighter wraps around smaller cogs/gears causes inefficiencies that don't appear on charts.

On my older road bikes (all 7-speed, usual dual 130 BCD chainring) the smallest chainring to fit was 38T. With the 50T big ring I had to try several freewheels to find one that didn't grind in the 13T smallest rear cog. Finally, last year, I gave up on the 50T chainrings and switched back to 52. That way I can use the 14 or 15 rear cogs without that odd grinding/resistance. It's still there when I'm in the 52/13 combo, but that's only on downhills. I can't hold a 52/13 combo on flat terrain for any time unless there's a tailwind.

For the past year I've mostly ridden bikes with 52/42 Biopace chainrings and 13-28 freewheels and cassettes. A week or so ago I switched my Ironman back to 52/39 round rings (same 13-28 SunRace freewheel). So far that's been good enough for our climbs, even into headwinds. I'm a very middling climber and would take any advantage I could get. But I haven't really needed easier gears ... yet. Subject to change with age. A few years ago I was satisfied with a 42 small chainring and 24 largest rear cog. I wouldn't be happy with that now.

I'm about to build up a newer frame, a mid-2000s carbon fiber frame from a friend, as a 10 or 11 speed. It'll be interesting to see whether a new, high quality 11-32 or comparable cassette also has that grinding chordal action in the smallest cog -- although I doubt I'll use it very often anyway.

Anyway, I can understand why the pro teams are finessing lots of little things in pursuit of small advantages, including oversized pulleys.