You can just pick Auto, or make your own custom gearing strategy if you don’t like the defaults. Not sure why AMR - Default is listed twice there… will see what’s up with that. Auto and AMR - Default are essentially the same thing right now.
Very soon, the “Auto” option will become much more powerful, but we’re still beta testing the new system. It will essentially pick from around 50-100 pre-calculated gearing strategies and find the one that best fits your current character (talents, legendaries, set bonuses, etc.).
I can’t speak to the accuracy of Icy Veins gear recommendations… no idea if what they are recommending is good or not. All I can say is that our defaults work very well for most players, but there is no such thing as a “one size fits all” gearing strategy (thus the new system we’re working on, and the ability to create your own custom strategies).
Here is a tutorial if you would like to try customizing: Stat weights - How to generate a custom gearing strategy