Ok, just got the PK3 and doing some A/B'ing, so to anyone that may be interested in this.
There ARE certain things regarding music reproduction that testing equipment cannot measure, and while I realize that much of this is subjective, my observations are as follows:
The MAIN difference between these two earbuds is that the PK3's take the veil off that are there with the Apple buds. Listening to the Apples, it's as if a blanket was thrown over loudspeakers and when switching to the PK3, that blanket was lifted off. With the PK's, I was able to pick up soft harmonics as well as decay sounds coming off of strings that the Apple buds just couldn't reproduce. The PK's are bit on the bright side, but I heard that things settle down with some usage.
The Apple buds have been demoted to back-ups.