I actually prefer the "old" interface for defining the mask region using native PS tools. What I don't like about the newer interface is that I can't draw the "compute" area without having the image obscured by either the "keep" or "cut" colors. In other words, it makes more sense to me to FIRST draw the compute area WITHOUT the keep or cut colors being overlaid onto the image, which obscures some of the detail. IOW, I'd really like to be able to see the original image without the semi-transparent red or green overlay WHILE I'm drawing the "compute" region.
This approach makes more sense both practically and semantically. From a practical standpoint, it's easier to see fine detail when it's not obscured by a semi-transparent overlay. And semantically, when creating a mask, I don't start off by thinking that I'm first going to either reject or accept the entire image. I start by thinking about where the boundary is between the portions of the image I'm going to mask and the portions I'm going to accept.
So please, allows me to draw the "compute" (boundary) on an unobscured image.
Having just started to get acquainted with Remask 2, I wholeheartedly agree with Steve's observations above. I think that the red and green overlays should ideally be optional during the 'painting blue' boundary stage, at least until the blue border line has been closed. After that, maybe a simple button to switch the red/green overlay on/off, so that smaller cut-outs can be made with precision?