Grover Huffman Speaker Cables

Hello all...  I have been using some Grover Huffman SX+ speaker cables for 6 months and absolutely love them.  I may want to move up the line but my question is... does anyone understand the line and what the differences are?  SX, SX+, EX, ZX, Empress etc.

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Ask Grover that dude is very smart.
“”””Groverh, please share your answer to the original question if possible. Thanks””””
I just bought a pair of 6ft SX cables to and compared them to what I previously had in the system 1.5ft CARDAS Cross/SPK Bi-Wire. 
In my system the SE sound better than the Cardas. The build quality is great and the price is very accessible for a high end cable. 

As I respect b4icu opinion on the calculation I do not respect the comment on the builder not knowing what he is doing. I just find it ignorant. 
I just ordered a full loom of Grover's cables.  He feels pretty strongly that he makes a good product since he'll take them back with no questions asked for a full refund.  In that case the only opinion that matters is mine.

BTW I believe power cables are snake oil.  Grover shipped me a Pharaoh version of his and I plugged it into my Don Sachs preamp.  The impact was immediate and completely recognizable.  I was prepared to ship it right back to him but I think it's a keeper.