The 5/8ths has more gain, but not so much more in a band and
application that is dominated by line of sight communication.

Funny, it's made a significant difference for me in the decade or so I've
been using them.

A folded monopole is almost as simple, and has more gain as well.
http://www.w4dex.com/kc4fwc/proj_2.htm

If the
difference between the two is important to getting into a repeater,
getting into the repeater is not the same as full quieting and can be
an obnoxious advantage suffered by those who have to listen to a poor
connection.

?? More gain is worse?
I don't follow you. Being able to run into the same machines at lower power
is always good for my batteries, and taking me from noisy to quiet on the
same power is always a good thing.

Such problems are more simply remedied by elevating the
existing antenna than trying to "add gain."

Altitude is king, as long as you don't throw it all away in the feedline.