It is not as good as IV. It still crashes and lags and glitches. Crashing wouldn't be so bad if it wasn't such a chore to start and load a game but in this game it is. V is more of a game and less a journey through the ages. I liked the journey through the ages. One example is that there are no graphs or playbacks at the end of the game. The game just ends abruptly. So that epic war you fought from 1300-1400 is just washed away by a painted image with a subtitle that says "You win. Click here to exit." There are numerous details like this (an ending!) that were overlooked for the sake of putting out a balanced war game.
If I knew then what I know now, I would wait until V was substantially price reduced. But since I own V, I play it quite often and I don't play IV anymore. My opinion is that V made some nice additions and changes to the game but at too great a cost in terms of removing the nuance and detail that made IV a classic game. Linear building in V is an example. In order to build a broadcast tower you must have built a monument, temple, opera house, and museum. None of these prerequisites have anything to do with a broadcast tower but they wanted the game to progress along linear lines (culture path, war path, gold path, etc). IV was much more flexible in terms of what you could build and it kind of made sense. It wasn't dead on historically accurate, but it was enough where I could say "Oh I see what they were doing here. They needed to have the powerful cathedral be limited somewhat, so they tied it to temples. That makes sense, you need to have a religious foundation to build grand religious buildings." There's none of that detail or nuance in V. It is very much culture path (CultureBuilding1, CultureBuilding2, etc), war path, gold path, smile path.
1UPT is nice enough but I find it a lot more tedious. I never really wanted to play a tedious war game. I basically wanted to play a game where I could war early to get a commanding lead and then play around with all the detail and nuance. Since it is a war game, you are limited by happiness and it is basically just a war game with happiness contraints. If you are winning at war you're only major problem throughout is happiness. Tech, economy and, by extension, culture and war are all rewarded by successfully conquering cities. The only thing left is managing happiness; which boils down to picking happiness social policies from a list and building HappyBuilding1, HappyBuilding2, etc.
The linear building combined with an inadequate ending leave me unfulfilled. It would be one thing to play a war game for 6 hours and then see a time lapse of WTH just happened. It gives the player a summary of what occurred. Instead the game just ends. It is a serious kick in the balls and that alone will make you wonder if this is really the game you just bought.
The AI is bad. Combat AI can sometimes put together successful attacks, but usually makes bad, glaring mistakes. Putting units in a lake for no apparent reason. Not using bombard adequately. Diplomacy AI is comedy. The AI is playing as if it was a video game player. I much prefer Civ AI to sim a great leader, but they went for an AI that sims a great leader playing a video game. That approach misses and the dialog is contradictory at points.
All that said, they are patching things up - buildings that do more than one thing, balancing things, fixing game crashes, unreasonable loading times, etc. Overall though, they are not patching in nuance and detail.
City states are hokey. They were billed as barbarians on steroids that you could do whatever with, but they are actually mini-civs that you need to buy off in order to play effectively.
I like hexes alright, 1upt is fine, cultural border expansion is nice. Those kinds of things they should have done, but they reworked so much more than that it is really disappointing.
Just to restate; if I could do it again today I would wait until it's substantially price reduced, but now that I have purchased it I play it often and have not played IV.
