Which modestly sized handguns perform best for you at the range?
Interesting thought you've got there.
I've got a .32 Seecamp that, considering it has no sights, will put 5 shots into 2.5" or less at 7 yds. all day, any day... with just about anyone shooting it. All stainless steel, it ain't no lightweight compared to today's "poly-tastic pocket poppers", but it's easy to carry in a pocket and sure feels good in the hand if you need it.
You may be right though about really tiny guns... especially when they are a large caliber for their size. At one time, the Seecamp was about as small as it gets (in a .32ACP)... now days, there are larger calibers in the same or I think even slightly smaller package.
Speaking of size, sometimes the sights themselves are more important than sight radius... and good balance (for an individual) can trump just about anything. I know lots of guys and gals that shoot their carry 3" Officers model size 1911s better than their match grade 5" Gov'ment models. Their Glock 26s and 19s better than their 17s or even their 17Ls and 34s.
I seem to be able to shoot better with most 4" barreled guns than with more or less length. I have a Colt Combat Commander (4") that I consistently shoot better than my Colt Gold Cup NM (5")... the GC is far "tighter" and is, admittedly, far more accurate off a rest, but off-hand, I do better with the CC. If I go down to a 3" .45ACP... I tend to suck no matter what.