Hex offers more realistic movement, with each direction being equal, and tends to divide the map better. It does also make it easier to compute distances, and makes movement, even for the player much easier and more realistic. Hexes also make the map look more natural, since there are much fewer right angles, and the hexagon shape is more appealing than the square for things like hills and forests.
And as far as Panzer General goes, I thought that that was about the best strategy game ever made. It was incredibly realistic, involved strategy and tactics on almost every level, was a great challenge, and was way ahead of its time. It's about 10 years old now and still easily beats out almost all of the new games coming out.