Huge fan of Catan, so I thought I'd take a chance on this. Unfortunately, I was very disappointed.
Visually it looks good, or at least enough for a board game based on Catan.
It handles all the rules for you so you don't have to stop the game and engage in debates. Not that you would with this version anyway (more on that later), and it includes all the scenarios and a map editor (though I haven't tried that yet).
Controls are lacking. The map can be squirrelly to navigate. If you're using a touch-screen it's nigh-impossible. When using my Windows 8 touchscreen laptop I kept flying off into some unknown corner of the map and tapping on buttons would cause other buttons to active. The interface isn't very intuitive and it doesn't have pop-up text to help with identification.
Buggy. As others have pointed out, it's buggy and prone to crashing.
No multiplayer. This is probably the biggest negative. It's on Steam. Why not let you play with other players who own the game? I'm guessing they don't want competition to their own multiplayer subscription site, but then why even bother with this version in the first place?
Graphics options. While the graphics look decent, the lack of resolution options is very disappointing.
TL;DR: The game isn't worth the asking price. I picked it up on sale and don't completely regret it simply because I still fire it up every now and then just get a Catan fix when I can't round up a couple more players for the board game, but otherwise this one just sits in my library collecting virtual dust. The biggest disappointment is how close they are. If they fixed the bugs, tweaked the interface, and added multiplayer through Steam, it would instantly be a classic.