Ok here is the bottom line:
It is a great game, poor activation issues (box-copy/digital download pre-loads, etc.)
The AI turns take FOREVER!!! I usually get up and pet my cat or do a chore or something in between.
The load times for battles seem bareable (but as I said, AI turns take forever)
System hog-15 gigs and needs a powerful PC.
Naval Battles-got bad reviews but I think they are fun, especially if I'm winning)
Grand Campaign is a wee bit diff, but it's a welcomed change
Tech Tree (research, 3 branches)
Wish more factions were playable, unless unlocked later (?) but i'm under the impression of no
Overall, A--. It gets one - for long AI turns, and another - for various little things (more factions, 15 gigs)
Hope this helps!!!
PS: Downloading this on my laptop now, wow it said it's going to take 8 hours, and I'm at home (wireless)