ARC PH7 upgrade


I currently have a PH7, which I am quite happy with. I saw AR is offering an upgrade to the power supply. For those of you who have done it, can you offer your thoughts, comparisons and opinions? Thanks.
jbecker
When you find out, let me know. I am ready to send my PH7 in for the upgrade, some positive feedback would be nice, but would ARC offer an upgrade that did not show an obvious improvement?
I talked to Dave Gordon of Audio Research at an event in Seattle and asked him about the change. He said there were two reasons you should upgrade: first, he thinks it improves the sound (he had just told one of his friends to send his back for the upgrade) and second, not only is the 5881 tube less expensive than the 2 6H30's but they are hard to keep matched during longterm use (don't have to keep 1 tube matched :)). I am going to send mine back in the nest several weeks.