I'd rather have a bigger pop cap than have nice graphics. As long as the graphics are functional I'm happy, but I realise that the rest fo the market is against me there, so it's not going to happen.
otoh it is possible for the game to get too big. I've tried playing Cossacks, and even with the ability to organise your troops into battalions, it does my head in. I think that's also partly because of the overcomplicated resource system (no-one needs 6 resources!) and tedious upgrade paths, and the significant but hard to remember differences between the civs, but the sheer scale of the game always bewildered me.