Joe .... if the review I clipped above is correct re the GSPre and GS150, I urge you to call Kal at ARC and ask him for his views.
The GSPre may look pretty, but it's expensive and may be a no-go showboat. IOW, not a cost effective way to spend your bucks.
In addition, if I correctly recalled what Kal told me about the Ref 150 SE, then the GS 150 is another pretty face that does not meaningfully outperform the Ref 150 SE. Yet, the cost delta is significantly more.
It's your money ... spend it as you will. Just trying to help a fellow A'gon pal make a cost effective and informed decision.
Regards,
BIF