Ian Jackson wrote:

...
There is not a lot of difference between the radiation of a 1/2 wave and
a 5/8 wave vertical antenna.

A 1/2 wave needs something like (typically) an L-match (low-to-high
impedance) at the feedpoint. As the antenna is voltage-fed, you can get
away without much of a ground (plane) system (but it does no harm if you
have one). Also, being voltage-fed, the insulation needs to be good
(especially in wet weather).

A 5/8 wave can be 'loaded' to a 3/4 wave by adding a series inductor.
The match to 50 ohms is pretty good. You do need a good ground (plane).
In the horizontal direction, it has a bit more radiation in the 1/2
wave, but not a lot. Mechanically, a VHF/UHF antenna 5/8 wave is robust,
and can resemble a simple base-loaded whip.

Essentially, you pays your money, you takes your choice.

Yes, my actual "hands-on" bears out your, above, text ...

However, after much experiments with differing form of matching schemes,
I have found a gamma match on 1/2 or 5/8 produces the most efficient
matching scheme I have attempted, others mileage may vary.

The gamma does distort the radiation pattern a bit, and can be seen if
modeled in EZNEC/MMANA-GAL, and it is actually seen in hands-on use, if
you rotate the gamma towards, then away from the station you are
receiving a very slight variation in signal can be seen, usually about a
meter-needles-width ... I consider it a very minor anomaly ... again,
others mileage may vary.

Even in a 160m, 50ft "flagpole" DLM, I constructed, this distortion, by
the gamma, is apparent ... however, it consistently shows up as 1
s-unit in hands-on use. I don't have open enough area around the
antenna to even begin taking measurements with a calibrated FSM, and end
up with anything near meaningful measurements ... indeed, surrounding
structures, homes, vehicles, etc., most-likely, distort the signal(s) to
a greater degree.

Regards,
JS