I generally play very small scenarios, company or below, so I wanted to see how much could be squeezed into 12 units or less. I've been surprised at how effective these units are. Cost is high, though.
I do a lot of 30H by 60W, up to 60H by 90W. Block a main road, hold a key village or terrain feature. Most of my playing while I'm over here is on a Microsoft Surface, 12" screen, less scrolling around with a small map.