I grew up on ZOCs.
No, it wasn't a breakfast cereal. It was the infamous "Zone of Control." All the earliest Avalon Hill classics had them, as did most of the old SPI quads and their kin. I learned about them so early in my wargame career that for a long time I gave them little thought, despite some articles in MOVES magazine about them. It was easy to forget what an artificial thing they were, and how they could distort game tactics.
Mastering the effects of ZOCs was required for good play in those old classics, but I don't think they really added much in the way of realism. One of the refreshing things about XTR's games was that almost all of them dispensed with ZOCs.
When you really think about it, a ZOC probably means that the there's a mismatch between the size of a unit and the size of the hexes. If a division can cover a 12-mile front then perhaps the hexes ought to be 12-miles across and not 4 miles across with ZOCs accounting for the other 8 miles.
ZOC rules lead to oddities such as occupying every other hex along a hex grain, whereas in actual operations you would generally occupy a more-or-less continuous line.
Overall, I think ZOCs are best dispensed with.