The color calibration issue has nothing to do with the slowness of the phone, yet it's being addressed in the project, so it does have more to do with than just slowness.
Second, if the efficiency of the OS is a focus of the project, then removing bloat should absolutely be on the list of things to do.
From the reports I've read, the lag fix seems a bit dubious in that it may cause more problems than it solves. As for the color calibration thing, I never found the color rendition on the phone an issue in the first place.
Now, if it removed Bing and bloat, I would be very interested. But yea, the dev has his own opinion about what needs fixing, so...