Combined Terrain vs Individual Terrians

I've been debating switching to a combined terrain for Apple Valley instead of the subhoods. That's how the world really works, right? Basically I would use one neighborhood map and there would be sections on the map to represent the three areas of Apple County, well-four if I decide to have a base hood university.

What about townies, downtownies and social groups?
As long as I have apartment buildings, then I will have social groups. These social townies pretty much nullify the need for townies and downtownies. I plan on having six sims in each social group for a total of 30 social townies. I would have a few teen townies, a countessa and count and a Diva and Mr. Big. The main difference is that in custom creating the townies, I would create relationships bewteen the townies (sibling groups, single parents, family groups, etc). I will also create six vacation townies for each vacation subhood (a total of four subhoods, one for each season which means 24 vacation sims).

Individual Terrains
(+) Pros
----able to use small terrains such as Amber's Journey with faster loading times.


(-) Cons
----load time of the subhoods
----seems silly to explain how far each subhood is to account for the fact that you can't see glimpses of the Metro from Apple Valley and vice verse.


Combined Terrain
(+) Pros
----lack of load time for each subhood
----simulated seamless neighborhood


(-) Cons
----not very many "medium" hood terrains. Most as either very tiny or large. I would want something that has a variety in roads to accomadate three different types of "subhoods" but is small enough to not have to scroll around without a camera hack to see it all. I like the Lake Crossing Terrain, but smaller with a lot less roads. I've been thinking of buying SC4 just to create the smaller hood I envision. I did finally contact Amber's Journey to request the perfect hood (a combination of three of her hood terrains). She just had a baby-congrats!-and understandably isn't playing the game as much. So we'll see.

The last question would be how to explain the new terrain from a FSBS prespective?