Hi,
I have a CAT SL-1 Reference that has been modified to be phono only. I haven't tried the PHD, but I recently purchased a K&K Audio SE Stereo phono kit with volume control off Audiogon. At first, I preferred the CAT as it seemed to impart more realism to the music, especially voices. The K&K also seemed bright at first. However, after about 3 weeks of listening to the K&K, I'm going to keep the K&K and sell the CAT. The K&K doesn't have the tube "warmth" of the CAT, but it imparts a larger and more realistic soundstage and also is also more detailed. It also seems to be more extended at both the top and bottom of the frequency spectrums. BTW, the K&K is a tubed unit with two 6N1P tubes. The build quality is great. The best part? The K&K is only $1549 in kit form. I'm not sure how much more the volume control and assembly would be. You can check with Kevin Carter at K&K. K&K actually runs a discussion forum at www.audioasylum.com.
Of course, the comparison I made was to the CAT SL-1; I've heard that the newer versions of the CAT preamps are less "tubey" sounding. Of course, they are also much more expensive than the K&K. If you don't have other source equipment, I think the K&K is a fantastic choice.