The first time anyone looks at the above window it is incredibly misleading. I've had a lot of questions regarding cloak synthesis, but without exception the one I get most is from people who are synthing their first cloak. The window above is incredibly misleading and I know a number of people have borked the stats on their cloaks because of this window.
When I tell people they want to select the "Keep current effects" option if they like the stat I get the following response without exception, "But why don't I want that attribute to go up?" This window makes it appear like you are choosing between keeping the OLD STAT or INCREASING that same attribute. The window needs to really change to be less confusing.
For those who don't know, if you select "Keep current effects" the stats you already have on your cloak WILL increase. If you ever select one of the stats below "Keep current effects" that stat will be re-rolled.