Here is a link to some info:
I recently got a set of his IC's with his base RCA connectors and while they are not completely burned in I like them enough to keep them. I have them between my AES preamp and a Sophia Baby Electric which I use with my AKG 1000 headphones. NOS tubes all around and the Stefan Arts cable on the AKGs. They replaced a pair of Audiodyne silver ICs with big WBT locking connectors.
I bought them after reading the links Matty pointed you to and some others, where a couple of respected voices stood out.
Needless to say this is a pretty revealing place to listen to cables. The big thing I noticed is that the music became more coherent - with the Audiodynes you tend to focus on the parts, with the Huffmans (Groovers?) you heard the music as a whole. Comparable levels of detail and black. Nothing too dramatic beyond the coherence (after 40-50 hours) because the Audiodynes are very good cables in their own right.
Grover is a kick to deal with, add to that a money back guarantee and some very reasonable prices and its tough to go wrong