I just finished grading a feature film using Colorista inside FCP7. Not a perfect solution, but a fantastic tool non the less. Was unable to use Color for the grading (could not find any good plugins for grain removal) and Colorista did a great job in conjunction with grain removal tools.
The S16mm film looks fantastic, even though the footage is 10 years old, transferred to 1080p digital files.
Being able to use multiple instances of the plugin allows for primary and secondary corrections + power windows. The new keyer is a fantastic addition to the package, and being able to reset individual colors within the wheel is fantastic. Any way you look at it, a MUST HAVE tool in every editor's toolkit.