Lack of integration with a Photoshop-centric (and in particular, ACR-based) workflow stops me from getting really interested in items like this.
At least DxO took the leap with their forthcoming 4.0 release to operate as a raw plug-in. It remains to be seen how well it works, because the just-published Beta left that part out (the part I was really interested in seeing, of course). I don't want it for its color balance, exposure control, etc. settings. I want to use it for what it really was invented for -- optical corrections for various lens/body combinations.
At the recent Photoshop Soup 2 Nuts workshop with Thomas Knoll, I challenged him and the other Photoshop developers that were in attendance to come up with a plug-in system for ACR, such that we could pick and choose from our favorite noise reduction, sharpening, chromatic aberration, etc software, and be able to use them at the most appropriate point in the raw conversion process.
While ACR does provide some tools like luminance/chroma noise reduction, I'd say that no one (not even Thomas) would defend it as best in class. Instead of trying to be the best in all things, it would be far more useful to provide a platform that would allow one to plug in their favorite pieces (seasoned to taste) and use them directly in their raw workflow.
I acknowledge that this may well be nigh impossible, given the way that ACR was designed and operates. On the other hand, Lightroom is prima facia evidence that one can re-assemble reusable bits and pieces of a given raw convertor and other filters/processes and present them in a non-destructive editing stack with a new user interface.
I'd like to see a good bit more progress on this front, perhaps with an industry consortium that can agree on the means for interfacing modules like this in non-destructive editing stacks (a kind of a DNG of photo editors, if you will). That way, DxO, for instance can concentrate on what they are really known for, instead of trying to also be a general-purpose RAW converter, as well, just so they have something to house their optical correction stuff in.