I'd like to
have some other way of measuring performance besides my uncalibrated ears
and the signal meter.

I can definitely appreciate the curiosity about exactly 'how well' the antenna
is working/behaving based on your design, but really, uncalibrated ears (and
sometimes signal meters) are about the only truly important gauges one can use
to find out if any given antenna is any improvement over what you had before.
IF you enjoy numbers and squeezing the last ounce of performance out of things,
that's cool, but most of the time I measure twice, cut once, and let my ears be
the main guide. The definition of 'best performance' has more to do with your
ears and the radio you're using than any noise bridge or antenna analyzer can
ever tell you.
Good luck-
Linus