I had a GCMAG with LW polygon and benchrest stock in .177 and eventually sold it. Not because I did not like its build quality and accuracy but because I prefer .22.
I got a new GCMAG in .22 with teakwood sporter stock last month. It was finished after a year and 7 months. Yes, the queue is long, and since the maker had only a couple of smiths and woodworkers, it takes at least a year and a few months before your order is finished. I have another order in the same configuration and is set to be completed by the end of the year (hopefully).
Now, if you ask about its quality and performance, I can say that it's at par with known and expensive brands like RAW and FX. It is not a multi-shot, as it is a swing/hammer-type but that doesn't really matter since it is usually used for competitions. It usually goes against the RAWs and FXs in serious competitions and funshoots or friendly games and sometimes win against them.
It is also not cheap. It will cost you around $1,000 (PHP 50,000) if you order it directly from the maker. Add more $200 if you buy it from resellers (those who order it directly and wait for more than a year and resell it for profit). The price does not yet include a carbon fiber cylinder and a branded barrel like LW. (Though the GCMAG steel-sleeved brass barrel is good enough for many).
Just like RAW, before AirForce took the small firm over, only a handful of staff make the GCMAGs. Is this a bad thing? Not for RAW and definitely not for GCMAG. They use "DIY" CNC machines for the T6 components and wood stocks. But they also use their skillful hands in manufacturing the units.
I have owned a few imported airguns in the past like Hatsans and Crosmans. Their quality is not as good as a GCMAG. I have friends and co-members in airgun sports shooting clubs that have RAWs, Thomases. Daystates, Brococks, the newest models of FX, etc. (Yes, there are a lot of affluent members of the airgun community in my country who pay up to twice the prices of US, UK, or Swedish-made airguns just to obtain them. A $2,000 or so RAW or FX Impact M3, for intance, can be had here for $2,500 to $3,000.)
Ask those using these expensive imported airguns here about GCMAG and you'd definitely get a positive feedback. Chances are they also own one ot two units of GCMAG.