The one unit per tile thing is one of my favorite things about the game. Although I loved everything about Civ 4 and previous civ games, I hated the giant stacks of death. They were stupid.
The problem wasn't that you could fit more than one unit on a tile. The problem was that there wasn't an effective cap on production towards the end of the game. No nation ever in history has had unlimited resources such that they could pump out true "stacks of doom."
You ask me, they should've used the kind of mechanisms from the latter two Europa Universalis games, where you had the following limits:
- Manpower: Each nation had a fixed amount of manpower available. You'd either have to hire mercenaries (which were REALLY expensive) or basically stop fielding units once you hit your max. Also, as you took casualties, reenforcements would come from your manpower pool, meaning that you couldn't build new units OR reinforce/"repair" old ones until the manpower pool replenished itself. End result: limited armies based on nation size and production capabilities.
- Force Limits: Each tile (actually a province) in the game had a set limit to the number of troops that could "live off the land" while stationed on it. If your army was too big, it would begin to weaken (as men died off or deserted). This produced two results. First, it made for a degree of tactically interesting combat. If you could hem an enemy in so that he had to wait on that tile before a battle, you could either force him to attack too soon, or suffer weakened troops. Second, it again limited the size of armies that could occupy a space. You couldn't just park a doomstack on a tile and leave it sit there for ages.
There are other limits that could be used as well, but I found those two to be a good balance of abstraction and "makes sense" gaming (not necessarily "realism," since that's a silly goal in empire building games).
I think the 1UPT thing could work well in other games (apparently it works perfectly fine in Panzer General, which served as the inspiration for the system), but
as implemented in Civ 5, it just didn't really work and created other problems like slowing production to a crawl in the early game.
Kind of interested, but does game have one of those eye gouging learning curves?
Not really, no. Actually, I'd say Civ 5 is one of the easiest games in the series to grasp, at least initially. That's one of the game's real strengths, in my opinion.
Anyway, all I'm saying is that I think, overall, as a game, Civ 4 was better designed. Civ 5 isn't bad, it's just not what it could've been and, in my opinion, not a worthy successor to its illustrious predecessors. That said, it can be fun to play around with, and for a bargain basement price...eh...fuck it. Might as well give it a whirl if you like these kinds of games. Just don't expect an evolution from the design of Civ 4. This is more of a radical redesign.