You've made me very curious, and since another person told me the complete pack is available for only 4 euros, I have no reason not to pick it up. The only thing that worries me is the stack of doom, and you seem to be an avid defender of Civ IV, so I want to ask you this: don't you think the fact that Civ V improved that stacking issue makes it worth playing?
Yes, SoD are probably the weakest point in Civ4. I have always maintained that posture, way back in 2004-ish when the combat model for civ4 was being discussed-speculated. I have always defended the "for-me" best solution, the Call to Power model where you could have unit holders ("armies") that combined their power and abilities in a little "combat simulator" window (look for Call to Power for more details). For the scope of a true Civ game, that solution is the middle ground and probably the "closest to perfection" given the constraints and the "spirit" of a true Civ game.
1UPT is a romantic idea, it sounds exciting and may even be fun, but it does not scale with what a Civ game should be. Civilization is not, should not, and never was before, a tactical game. 1UPT is a tactician's heaven, and it has its place... in WARGAMES.
To make things worse, the AI has no idea of how to use 1UPT in Civ5. That gives the illusion of "brilliance" to some players (easily defeating the AI in a tactical battleground), but sooner than later it becomes clear that the AI cannot handle it at all, and that the challenge is not there.
Some optimists say that AI could be made better, but I doubt it, simply because the 1UPT model does not fit the "grand strategy" scope of a Civilization game.
SoD are closer to the other extreme, but saying that "you put all units in one big stack rinse and repeat" is an over exageration, to say the least. There is some thinking to be made when dealing with the stacks, and it is not true that One big stack defeats everything; but the best is that the AI can at least handle it, and the BetterAI is a nasty user (and does not necessarily put everything in one big stack).
You have to try it. As I said, SoD are probably the biggest weakness of "Four", but you will find so many more strong points in it, that you may "forgive" the SoD model...
Try it.