Remember that the control points are subtractive so you can remove areas from the target control point by placing new control points on the areas that you want to remove. I find I can get pretty good isolation by a combination of other control points and moving the target control point around. The draw back of this is that I sometimes have to create a new Vineza layer to work on a different part if the image as the extra control points conflict with another target.
There is a new version coming out soon, not sure what it adds, but it would be nice to have:
1) color selection
2) ability to combine control points
I just started using Viveza 2.0 a few days ago. It now has a set of sliders for global adjustment, including brightness, contrast, saturation, shadows(lighten or darken), levels, curves and others, and it adds "structure," which is similar to Photoshop's Clarity slider. Structure was available in Silver Efex, and I wished it had been available in all of the other NIK filters. I also often wished Viveza had global adjustments, since after doing the local adjustments I often wished to be able to tweak the global image without having to return to Photoshop proper. It is now possible to do the global adjustments before or after the local ones, and tweak either before committing.
You can also select a group of U-points and adjust them as a group. I wish that there were something other than a rectangular selection tool, as not all of the points I would want to group fall within a rectangle. I haven't experimented with additive selections, though, and I might be wrong.
I am extremely pleased with Dfine 2. I also use(d) Noise Ninja and Neat Image, and I find Dfine at least as flexible with at least as good results, with a much more intuitive approach.
Most of my B&W conversions are done with Silver Efex. While there is nothing per se that I couldn't get from Photoshop, Silver Efex is quicker and at least as useful. I just wish that the color sliders in Photoshop's B&W adjustment layer were available as a panel in Silver Efex, although to a limited degree, similar adjustments are available if one chooses to emulate a film type and alter its color sensitivities.
Color Efex can produce extremely subtle effects and becomes part of my workflow for almost all of my images.
The NIK people really understand how photographers work, and have become a permanent part of my work, along with Focus Magic (a great deconvolution plugin) and QImage, which I use for printing with my Z3100--it makes printing easier than using PS, and allows me to override some of the limitations of the HP driver.
I do not work with or for the NIK Software folks; I just love their products.