interesting that you say that aatami, since I had a similar experience, I couldn't imagine going back to civ 4. otoh, like Sulla, I suspect that is because I have played it to death before civ 5 came out. What I realize when I play civ 5 is that I am bored. not "civ4 I have done all this before" - bored, but "there is no variation here"-bored.
there are numerous reasons for this, the tile yields certainly make things boring. the low difference in yields make cities bland and indistinguishable. another problem is the tech tree, it's a boring linear progression with few strategic choices, no real paths to choose from, just grab everything (you'll have to in order to progress), and illogical connections. Chivalry leads to Banking? Economics gets me windmills? ok... whatever, that's not the real issue. I need to tech the naval path even if I am playing on a pangea with no coastal cities? still not the point, just minor annoyances. the main issue I realize is that everything is just a slight improvement on what you had before. First I get monuments, then I get temples, then I get opera houses and so on. first I get barracks, then I upgrade to armory, and then whatever comes after that.
Every building is a linear ladder, build new building for slight improvement. keep doing so from 4000bc until you're bored out of your mind. same with units. I start with my warriors, who become swordsmen, who become longswordsmen, then I have to skip a step since musktemen are weaker than longswords, and then get back on track with rifles, infantry, etc etc.
Every unit, every building, every tech is just a small improvement on its predecessors. developing my civ is utterly meaningless and boring. all I do is upgrade units and buildings. for hundreds of turns! the peace-time aspect of the game is in my opinion absolute crap, and the only reason we haven't realized is because occasionally a war breaks out that is exciting and requires our attention, the civ merely runs in the background while the wars are fought, and you hardly notice it is there. building new units is near pointless if you need them quickly, just buy them and continue to have your cities upgrading their libraries into universities. by the way, what the hell is the notion that Universities are a prerequisite for public schools..?? not the point, again.
as for the hex tiles, I like them. as for the fighting... I recently played a lot of panzer general, the original, for some reason I can always come back to that game and love it. civ 5 does not inspire that feeling. the combat system has some really cool ideas, but it just doesn't excite me enough, especially since civ is not supposed to be a war game. which seems to be what it has become. in every game I have played I have gotten bored by the industrial era and just gone off and conquered all enemy capitals.
I am disappointed in this product.