In CivIV you could clearly see why someone liked or hated you (in the screen when you're talking to the other leader). In this perspective I also miss the civics. If I was, for example, talking to a leader of a theocratic civilization and I had free religion, this really influenced our attitudes towards each-other. We have the social policies now, but that is pretty much a one way thing. You choose ones policy, then the following steps of that policy, but there's no way back (and no reason to want to go back). Other leaders don't seem to bother what policies you choose (or at least that's not clearly shown). In CivIV you could have good reasons for switching from free religion to theocracy, with other leaders hating or loving you for that. The social policies don't seem to have this kind of effect.
Furthermore, other civilizations, which have been friendly towards you all the time, can sometimes declare war on you for no good reason. And after the war they can be instantly friendly towards you again, while I would suggest that a war would have an effect on diplomatic relations for at least one or two decades. In CivV you don't seem to be able to have 'game-long' friends. Anyone can declare war on you at any given moment for no apparent reason.
But anyway, like I said CivV is still a really enjoyable game. And I'm just going to have to deal with the differences forom CivIV or play another game of the latter.
Clear numbers don't add depth, they add transparency, there is a difference here. Transparency is exactly what CiV needed really, but I think they achieved that with G+K and the greyed out modifiers.
Civics in IV had absolutely no influence on diplomacy whatsoever. A tiny +/-1 is barely worth mentioning. The example you gave concerns (yet again) religion. In CIV diplomacy is defined by religion, most civs love or hate you entirely based on your religion. It was its biggest failing IMO, it's neither realistic nor historically accurate or fun. In one of my latest CIV games Caesar threw 4000 years of peace out of the window and DOW-ed me just because he converted to Taoism 11 turns ago. Taoism, the most aggressive religion in the world, right? I was 15 turns away from getting Free Religion, but I guess he couldn't wait. 4000 years of cooperation, trade, mutual friendship and peace down the drain because he converted
I am sorry, but this is
stupid. I understand why some people like it and indeed religion is a great tool for creating the diplomatic blocks that
you want and messing around with the AI civs, but I never was impressed by diplomacy in IV. Still can't see the depth, it's all about religion.
As for your second point - I guess I must be lucky, because aside from obvious backstabbing, I haven't had friends DOW me since G+K. In my last game I was friends with Spain the whole bloody game, from the moment we met. Havng friends is very much possible. Maybe I haven't played enough, I play Huge Epic games.
And it seems you guys still haven't understood this - in CiV when a leader is "Friendly" that means he or she
wants to appear friendly, that
doesn't mean he/she actually is friendly. A good example would be Liz, she always goes friendly right before she attacks you. The game does a good enough job to make it clear when an AI is trying to deceive you, and when you see a "friendly" Alexander, with whom you have only negative modifiers, marching an army towards you, well, I think it's safe to say he's lying. Was this design decision the right one? It comes down to taste, but I personally like it. Finally backstabbers sometimes actually surprise me, in IV old Capac always went Cautious for no reason when he was getting ready to DOW you.
So I am sorry, but I still don't see IV having any diplomatic depth whatsoever. If anything, it
lacked depth because of the ridiculous influence religion had on it.
As for V, now after G+K I really,
really like it. The diplo has almost entirely been fixed, religion is exactly what I was expecting from IV, being a builder is actually fun now, the tech tree is good enough for me, and I really like SPs and CSs. It doesn't have as many features as CIV, but especially in the late game CIV sometimes became a chore. you had to micromanage your cities, keep a track of their health and happiness, spread you corporation, watch out for that espionage bs, it was just convoluted. CiV on the other hand took it a bit to the extreme with the streamlining, but after the expansion... Well, it's still missing some features I am desperately craving for (foreign trade routes, war weariness and local health), but I just find it more... fun. I like roads having a trade-off, I like the concept of building maintenance (Master of Magic says hi) because it really encourages you to specialize your cities. I also like how the game doesn't go out of its way to stop you from ICS-sing, but rather makes tall empires just as viable as wide ones thanks to SPs and Nation Wonders. In IV by contrast bigger was always better, the trick was how to get bigger. I don't see why people say that it has less replay value, thanks to each civ actually being unique and the surprisingly deep religion system I find myself adopting a different playstyle every time I fire up a new game.
In conclusion, I really like V, I think it's a worthy addition to the franchise (I like it a lot more than III for instance). It's not perfect, there are still some silly exploits and wonky mechanics, but after G+K I find myself playing it a lot more than any other Civ game. Every now and then I would get a sweet tooth for something a bit more feature-heavy, load up IV, enjoy a game or two, and then get back to V. Maybe I am a casual gamer and deserve to die in an agonizing way because I encourage the dumbing down of one of the last big franchises found on PC, I don't know. But I really enjoy V. And it's also the first Civ game where I don't absolutely despise any kind of warfare.