Mike...the scuttlebutt is that ARC will be coming out with their KT-150 based Reference amps sometime in the next year (even though you can drop in the KT-150s into the current Reference amps as well with a supposed jump in SQ) and my sense is you will get even more SQ at less than GS-150 prices with the next iteration of the Reference amps. part of what you are paying up for in the GS-150 is the bling factor aimed at the Asian market.
There are some folks who have tried the GS-150 as compared to current Ref amps fitted with KT-150 tubes and have said the GS-150 beats them on SQ but this is a few peoples opinion who have had the opportunity to make the comparison. There is a big thread on that other site you know well that I can provide a link to here if you wish which goes through the back and forth between various members and it gets quite "energetic" let's say but for what its worth, my opinion purely on what I have read and that old common-sense sensibility tells me you'd be better off waiting a bit for your next iteration of Ref amps based on KT-150 tubes or even get current amps and drop in the KT-150s.
Now if you like the aesthetics of the GS-150 and that's part of the allure than go for it. By the experience of a few people and a few reviews out there, it's quite the amp. As for the fans, there are two things you can do:
1) is turn them off and just keep the amps on amp stands with plenty of ventilation or
2) you can have silent fans retrofitted without much effort that can bring the noise level down.
Just my 2c.