Yup, what Earl said on all counts.
Fwiw, when the GC 12s first came out long ago, I was excited. I love the GC body for its very comfortable dimensions and focused tone. I am also a long-time devotee of Taylor's 12 as the absolute benchmark for 12-string playability, period. So it was with anticipation that I expected these to be great; I was disappointed. Not one GC but several, at diff shops, over time: the build is simply too small for all those octaves for my taste. For a purely live guitar in a full band context, then yeah, I think this guit would excel as your bassist and drummer are going to handle the thump. But for playing solo, a 12 requires bottom end, good amounts, IMO. I used to own a jumbo which was great, but had finally arrived at the GS body to be their best 12, best size for deep bass to balance the jangle, but not so big as to be unwieldy.
In today's hotly contested market, it's no wonder models face the chopping block: witness the AD series, perhaps a trimming of the GT, and unexpectedly, the intro of the Legacy line arguably to shore up diminishing sales (pure speculation, of course). I don't "think" there were many GC12s made, but if one has that specific hankering, finding one used is likely your best at a good price.
Edward