I was a K701 fan and went through a number of amps until I found what I thought was a terrific match, the WA6se. Prior to the WA6se the k701 sounded a bit thin, still enjoyable, but always felt like something was missing. With the WA6se and the right tubes the K701 came alive with amazing performance with jazz, classical, acoustic guitar and vocals, with nice bass and incredible sparkling clarity. I was absolutely addicted to the detail, and everything else I tried sounded dead in comparison... until I tried the GS1000. The GS1000 in my opinion takes all the good points from the K701 and adds a deep bass and fun engaging sound that just makes you keep listening. I owned both at the same time and within a day decided to sell my beloved K701 as there wasn't anything it could do that the GS1000 couldn't. As another bonus, the GS1000 can sound great with any genre, from jazz to metal, where the K701 was strictly a jazz/classical/acoustic can. My K701 became much richer and musical after 200hrs of break in, but admittedly there were still a few moments where the highs would bite me, the stridency on certain recordings was a little fatiguing. The GS1000 doesn't have any stridency or sibilance. In fact it has a sound that just allows me to melt into my chair and listen to anything in my library with absolute relaxation and comfort.
*edit* one more point is that the K701 wasn't very forgiving of poorly recorded music, while the GS1000 isn't as picky, and sounds good with anything I throw at it, and stunning with well recordded tracks.