just to add one thing, you say:
the effect is a zoomed out image, with everything smaller. I find it harder to see distant enemies
What you describe is exactly the point of raising the field of view.
It's like using a wide angle lens, so it's obvious that everything is smaller, but if your monitor is bigger, then it will compensate for that. Vertical fov doesn't play a role in this. At most it's useful if you don't like 'fat' players
Did you change monitor? For instance when I started ET I played on a 4:3, 17'' screen, the base of the screen was 34 cm (not the diagonal)
Let's assume I used 90 fov, now what's the fov for a 16:9 monitor with a base of 50 cm? (note that I don't even care about the resolution here, if I want the same size, resolution doesn't play a role)
90/2 = 45, so 45 degrees are 34/2 = 17cm in my old monitor.
I want in the middle of the new screen the same size as the old. 50cm/2 = 25cm, this is the half of the new screen.
So if 17cm is 45 degrees, how many degrees is 25?
the tangent of 45° is 1, 25/17 = 1.4705882352941178, so I want an angle whose arctangent is that.
here is a website where you can do the calculation but you can use a spreadsheet or calculator, jsut pay attention to the fact that angles are usually in radians not in degrees
arctan (1.4705882352941178) = 55.78429787 it was half the screen so I multiply *2
and I get FOV = 111.56
this way I will have the same horizontal size as my old monitor, plus 2 extra parts at the sides