I've been playing Civ4:BTS. I'm up to 1952 now and am on the cusp of victory... though I think I'll leave off on the victory bit for a while. I control a complete continent plus about a quarter (each) of two others. I invaded with huge stacks of Tanks (28 strength) and only late into the war was able to upgrade them to Modern Armor (40 strength). I'm thinking of crippling Pericles (Greece) in a short but bloody war.
Since I'm playing the Next War mod, I'm thinking of avoiding fast victory. I want to build Automatons (cheap weak clones) or Cyborgs (cheap stronger clones) and simply pile Greece that way. At this point, either choice would be stronger than his typical Riflemen. I've such a huge tech advantage that it's silly.
Next time I play, I'm going to have to bump the difficulty up one or two. I'm getting pretty darn good at clearing my continent of opposition and then teching to victory. This game has, more than anything, been in my favor.