I've read the RPS and Joystiq reviews, as well as some of the other chatter happening around the tubes, and I've come to the conclusion that there are a lot of misnomers out there about Civ 5's mechanics and its impact on the franchise. Without further ado..
1. One-unit-per-tile is not necessarily "better" than unit stacks
There seems to be this prevailing wisdom that OUPT has been outed as some sort of glorious revelation. In the dark days before, we walked up hill both ways in three feet of snow in order to play a 4x game with stacking. Nowadays, however, we've advanced beyond such -dated- and -ridiculous- combat mechanics as stacking.
The truth is, it's all bollocks. There is nothing inherently -better- about either approach. Here are two reasons why:
a. Strategy vs. Tactics
My first issue with this argument is that it refuses to see the distinct impact these combat mechanics have on the game more generally. OUPT combat encourages tactical thinking, with positioning, range, land type, and other "local" features dominating the process and outcomes of warfare. Stacking, however, tends to result in combat being more macro-based. You win wars by making the best use of your resources and being prepared, diplomatically or otherwise, for any situation. Of course, neither Civ 4 nor Civ 5 are completely tactical or grand strategy. But the distinct combat mechanics do tend to result in different emphases on each game.
In Civ 5, you'll need to spend more of your time on positioning, approach, formation, etc. In Civ 4, you'll spend more time on your cities, advancements, micro-mechanics, etc.
b. Stacking isn't necessarily mindless
Another issue I have with the party line is that stacking is some sort of mindless activity. You simply dump all of your units in a stack and, hey, go destroy. The truth is that Civ 4, especially in its best moments, accomplished quite a bit more with stacks than that. Also, even beyond Civ 4, there is a lot of room for making better use of the stacking approach.
For example, during the end-game, war became actually pretty multifaceted. You need to have your reinforcement lines upkept to keep your troops in decent quantities. You need to have bombers and fighters in decent locations in order to support combined arms invasions of highly fortified cities. Prime points for bomber strikes or reinforcements became natural targets, which would be defended with harsh resistance. In order to take a city, you'd often have to bomb its fortifications to submission, weaken defending troops with suicide strikes and artillery bombardments, then try to establish a final breakthrough with your armors. Depending on your reinforcement route, you could either leave infantry behind to quell resistance and defend the city itself, or fly in paratroopers to help with the task. Combined arms utilization and road mobility were central elements to the combat in the game. It wasn't all "stacks of doom." Even in the early game, stack composition mattered greatly, and it shifted depending on what kinds of resistance you were facing. Overall strategy was still central to conflict in Civ 4, but tactical elements were involved, especially in ways that were highly entangled in the greater strategic environment.
Even where Civ 4's combat had issues, there are solutions other than the OUPT approach. Supply rules. Less stringent restriction on unit spacing. OUPT isn't the one-and-only answer.
2. Simplicity isn't necessarily better
Another argument often made about Civ 5 is that it dropped all the "bloat" of its predecessor. From this perspective, while Civ 4 was fun, it was overly complicated and confusing for its own good. Civ 5 did away with the confusion and, in the process, made a game that was cleaner, clearer, and more fun.
However, again, there simply isn't anything -necessarily- better about a simplified approach. Here are two reasons why:
a. Clarification without simplicity
If there is one thing I honestly like about Civ 5, it's the interface. It's smooth. It's milky. It's polished. It makes sense. I was asked recently what I like most about modern games. I said the interface. With exceptions (*cough*Skyrim*cough*), modern interfaces are just far better than in the olden days, and Civ 5 is no exception to this rule. It's interface is head-and-shoulders above its predecessors.
However, I think there is a conflation, on the part of many gamers, of the interface's simple quality, and the overall simplicity of the game. In other words, I think people took the excellent interface as a sign that -complexity- itself is undoubtedly a bad thing. And that's incorrect. Superior interfaces improve all experiences, including both games with simple concepts -and- games with more complicated mechanics. If anything, I think UI improvements are -more- important in complicated games than in simple ones. Sometimes, a good UI can save hours of instruction book, patch notes, and forum reading.
So, simply enough, I want to call on people to carefully differentiate Civ 5's excellent UI and its mechanical simplicity.
b. On depth in the Civ series
Although I still enjoy Civ 5, and I understand why people like it, I can't help but feel that Civ 5 isn't a sequel to Civ 4 at all. It's actually a sequel to Civilization Revolution, which started as an attempt to bring Civ to consoles and which also lead to an iOS release. I haven't played the original console version, but I have played the iOS release extensively. It's very fun. It's Civilization, only with a speed, simplicity, and sense that makes sense in a mobile environment.
However, after I played a few games, I came to realize.. most of these games ended up being rather similar. My choices were often restricted. Whole pathways of the game that I was used to were gone. Little features, like in-depth statistics, a true ending, the palace, city details, advisors, the top 10 lists, etc. etc., were all missing. At some point, I just felt empty playing the game. It felt sort of generic and heartless.
After playing a few games of Civ 5, I quickly caught on to the similarities. The solid interface. The simplified mechanics. The lack of mechanical depth or flavor stats/lists/city details/etc. The lack of options. Civ 5 is a game that is easy to start playing, but, IMO, easy to stop playing. It simply doesn't root itself into as deeply as its predecessor.
Recently, I've been playing some Alpha Centauri. It's really amazing to match SMAC/SMAX and Civ 5 up back-to-back. It gives you a sense for, despite some common genes, how different these games have really become. They basically represent different feature sets, different challenges, and different experiences. I mean, in SMAC/SMAX, you design your own unit types. Consider how that stacks onto the strategy vs. tactics argument discussed above.
For some people, Civ 5 is more than enough. It's easy to learn. It's fun. And it's highly polished. The OUPT approach is perfect for this group, as the strategic elements are self-evident. It has a euro-board game style of abstraction that matches well onto short, fun gameplay sessions.
There are also a few other games released recently with similar strengths. Warlock: Master of the Arcane is also good for a few short campaigns. Endless Space, thus far, hits on a lot of the same tendencies.
However, for my taste, I want a game meant to be dug into. I want a game that will tell me my whole story with statistics, advisors, excellent narration, temple improvements, and tons of options. I want the interlocking mechanics to balance each other out, so there isn't just one focus or one approach. I used to be sure that the Civilization series would provide that level of depth, but I understand that it can't now. I hope the rest of you enjoy it. Just remember that it's not a clear-cut, black-and-white improvement. It's its own thing, with its own set of strengths and weaknesses. If Civ 4 is 4x, Civ 5 is 4x-lite.. and that's not necessarily a bad -or- a good thing.