only played one run through so far (Greek, military victory on easy). There're good and bad points. I like the hex grids, and got used to the no stacking rules pretty quickly. Combat is... Ok. The new predictor could do with being a bit less accurate - takes a bit of the excitement out of fighting. I also love the fact that i can build a giant death robot.
Overall though, i think there're a few more negatives than positives. First off, performance is a dog once you get a big empire. Admittedly, i'm at least a generation behind current hardware, but for a turn based strategy hand it's painfully over graphical. I'm definitely going to have to tank the graphics for next time. Also, and i know it's terribly non specific of me, it's just ... Lost the vibe of number 4. 3 and 4 got of hooked straight away, but 5 feels a bit like a struggle, a chore. I think it's because the timing is off - it takes too long to do anything at the begining, then everything happens too quickly to take stock of new events. I'm going to fiddle the speed and difficulty settings and see how i go before i give up though.