I have no experience with anything other than AO which I have used
for many years. I purchased A.O. because it had the ability of
analysing any given radiator over different quality grounds and also
for it's ability to change the geometry of a radiator so that gain,
swr, F/B e.t.c can be optimised depending on your requirement.

So can 4nec2. It's optimizer was based on the same principles as AO.
Furthermore it can (almost) automatically convert *.ant files to 4nec2
input files. (just specify your *.ant file as a 4nec2 input file).
Besides that 4nec2 is based on the nec-2 core whereas AO was based on
the mininec core, especially important when modeling 'close' to
ground.

It is also a great learning tool because you can see where major changes
occur while the program runs that gives you insights as to
what further changes you can present to the program and follow the
computors progress as it changes geometries e.t.c.

I would suggest to take a look at the 4nec2 'evaluate' option. With
this you can stepwise change one or more antenna, ground, load or
other dimensions and see what effect they have on far-field pattern or
other antenna characteristics.

I have just purchaes the A.O. Pro program which cost $300.
This program is the same as the std A.O. program except it has many
more pulses available e.t.c.

4nec2 max is 5000 segments for XP systems, max 11000 segments for
none-XP systems

As far as I am aware the A.O. program can achieve what most of the
other programs can achieve whereas most other programs cannot achieve
what A.O. can achieve which really tells the story.

I would be very glad to know what you think could be added to 4nec2 to
make it even better.

Furthemore it might be usefull to know the following is also possible:
- Switchable genetic based or traditional hil-climbing optimizer
- 2D, 3D graphical- and chart- display of near-field data
- Optional surface wave-data included in far-field.
- Sophisticated Smith-chart display when using frequency sweep.
- Interface to VOACAP propagation prediction freeware
- CAD alike geometry editor for starting modeler (however not usable
when optization is required, see help-file)
- Nec-2 aware or default notepad editor also usable.

One drawback might be the lack of a very comprehensive getting started
and/or user manual, but you can always contact me in case of problems.

Please don't interpret this as an advertisement. Just as an attempt to
share some private-made software with others interested in antenna
modeling and/or propagation prediction.

Arie.