I have the 10spd version - moved across from SRAM Red as my new frame was Electronic only. Price wise I couldn't justify the Record EPS I wanted (totally based on looks) as I got the bundle for $900. I love the usual stuff that everyone bangs on about but there are somethings that I'm not totally in love with.
Cons:
Pretty Ugly - the RD is massive and butt ugly, the new version looks almost as good as the Dura Ace so if you're wheels can be converted to a new 11sp freehub with a slight redishing then I would totally go for that.
FD is wide - I have pretty big calves and if I get sloppy I can rub them on the outside of the FD body, depending on your leg size this may or may not be an issue. Newer version looks way more compact.
Control Junction can be hard to place in an aesthetically pleasing location. Its anal I know but it took a long time to find the best location and routing for this little gizmo. The newer control box fixes under the stem, which you will need for the seat post battery as well if you go that upgrade.
Battery - large and in charge depending on its location - if you can spring for the seat post one do it.
Hood Shape is wide and flat - personal preference but I much prefer the ergonomics of SRAM and Campag. Not used the newer hood shape.
I have seen the latest version for less than $1000 (Upgrade kit) using vouchers and would swing you that way if you could get your existing wheels to work. I have read that you can run it with Campag Cassettes fairly effectively but thats just interweb chatter and not rooted in my own personal experience.
Edit - I was trying to give you some cons to work with but in all seriousness there is simply nothing wrong with the performance of this groupset and all the little niggles I have are easily overlooked. Its also nice to know that in the event of a crash I won't have to fork out an arm and a leg to replace any items.