I too liked DD a lot and have played it all the way through three times and part way through several more. DD is the reason I became a kickstarter backer of OS.
I agree with most of Mixxer5's points. I would have been very happy with an updated DD-like game, but that's not what we got. There are many things I like about OS such as its crafting and the flexibility of setting fire to oil slicks, etc. My main concern is with the fights. In DD, the PC often encountered minor enemies, such as a wild boar. These fight would be over in a few seconds with minor reward, typically a few experience points and maybe some meat. So far in OS almost all the fights are major affairs, often lasting 20 minutes or more. A few of these are fine and there is a joy in discovering how to win against seemingly overwhelming odds, however not all of them. More frequent minor fights would be very welcome.
Beyond the fights and issues Mixxer5 mentioned, such as linear versus open world, I need to play the game a good bit longer to really decide how OS stacks up with DD.
