When I test-rode some bikes last June, I hadn't ridden a road-style bike in over 25 years. I liked the bike well enough (Specialized Sequoia), but the next day I woke up with a sore back and started worrying about the riding position. So when I bought the bike I replaced the stem with one with a higher angle.
Well, the back soreness was apparently just a matter of re-stretching my 60-yo body, because it's never happened again and I can even ride comfortably in the drops and in fact I now feel like I'm sitting a bit too high when on the tops or even the hoods (especially on a windy day!).
Both the original stem and the one I put on are 120mm Specialized "Pro Road" stems that came with a set of shims that let me adjust them in 2-degree increments. The original was a 12-degree shimmed to 16 degrees and the replacement is a 24-degree with a zero-degree shim (IOW, I changed the stem angle from 16 to 24 degrees).
My question here is how much difference a couple of degrees really makes for a stem. Changing the angle of course moves the bars both forward and down, so there's a definite effect. Do you think that I should just put the stem back at 16 degrees (-8 from current), or should I try something more radical like 14 or even 12 degrees?
As I said, I can combine stems and shims to go all the way from -24 to +28 degrees in 2-degree increments, but that's too many combos to try out! At least it only takes a couple of minutes to make a change, so I could even change it by the side of the road while experimenting.