goglier: I highly recommend it, even though it is, unfortunately, a steam-only title.
Pangaea666: This monopoly practice needs to die. People rave about the free market, and here is another fine example of hating the free market and instead putting in limitations to ensure monopoly (even if somewhat limited and more on a by product level). When I go to shop food, they have cheese and milk and bread in the same store. I don't have to go to three different stores (although there is of course some of the same free market hatred going on there too, with smaller brands finding it close to impossible to get into the main stores, at least where I am from).
I dislike the fact that newer Paradox titles require Steam to be installed, but I can't exactly blame them for making that decision either. They created a DRM-free version of Crusader Kings II and the financial result didn't justify the expense. Plus, even among the DRM-free crowd, there is enough people that are willing to accept the compromise of having to use Steam to install the game, but being able to play the game without it that it (unfortunately) makes a non-Steam version even more redundant.
I just wish Paradox would put their older games on GOG already, since none of their justifications regarding not being on the service apply to their games that already have DRM-free versions. I'm also very saddened by the fact that East vs West was cancelled; not only was the concept great (there really isn't enough Cold War games), but the developers also promised a non-Steam version. =(
Anyway, I haven't played EU IV, but EU III was fantastic and is also easily available outside of Steam (I have the retail Complete collection, which includes the base game and all the expansions). If you're not sure about EU IV, you can try out III; it's pretty cheap and easy to obtain nowadays. Besides, considering the sheer amount of expansions and DLC Paradox has been releasing for their latest titles, it's better to postpone purchasing them until a later time.