Hi. I played CiV when it first came out and I thought that it was a huge disappointment after Civ4 - Bts. At that point I agreed with most of the comments in the CiV-Rants thread and stopped playing the game after a couple of weeks. Needless to say, I have nothing against the people who like this game. I still play Bts regularly and I am not bored at all.
I do not know much about the current state of the game (Brave New World) and I would really like to know your opinion. Do you think that it is much different/better than before? Or is it more or less the same? What do you think?
To be honest I cannot make that judgement for you.
I suspect the longer you play Civ IV BTS the less likely you are to embrace Civ V.
Civ V on debut was a good idea that was unfinished, and as such had many issues balancing, bugs, exploits and missing BTS features.
Over the next year there was about a half dozen MAJOR patches that significantly altered the gameplay and did a good job of restoring game balance for the most part (As well as squashing many of the bugs).
7 DLC's were released (primarily new civs and scenarios), usually proceeded by a patch.
GODS and KINGS (Expansion 1) reintroduced RELIGION and ESPIONAGE (lesser mechanic) to CIV V, also added Melee Naval units, expanded the tech tree layout a little (added a new age, but more a rejig then a major addition). G&K also greatly increased the depth of the Diplomatic AI. G&K also first introduced IDEOLOGIES into the mix and enhanced the role of CITY STATES and altered the nature of combat.
BRAVE NEW WORLD (Expansion 2) on the other hand greatly expands upon the end game, introduced the WORLD CONGRESS, IDEOLOGIES and TOURISM mechanics as well as greatly expanding (for the better IMO) the Culture Game (both the Victory and the Mechanic).
Both expansions added quite a few other more minor things too like new civs, new wonders, some new techs, new natural wonders, new city states, new social policies etc.
I would strongly recommend you give CIV V a go. It really does stand up on its own two feet now and is an exceptional game in its own right. BTS was great but CIV V is now better IMO. That said it is different, and if you can only look at what BTS has that Civ V doesn't (health resources and corporations for example) and not the reverse (ie city states, social policies, more in depth diplomatic AI, AI that play more to win, hexs, 1UPT, UI, UGP, UA, an interesting and immersive take on religion (much better then BTS) then you will likely not have much fun playing it.
If you do give it a go, remember that the core game is very similar, but the mechanics can and do vary. Some BTS strategies will fail wholesale if applied without consideration.
Anyway hope that helps.