Greyboe is a company started by McMillans son. He was given rights to the A5 and has created a process for an injection molded stock instead of the hand laid fibreglass like McMillan.
I just purchased one and really like it , feels great and seems very solid. A few things I did notice, if you like the texturing on the foreend and palm swell then you will need to do afterwards . You can have an adjustable cheek riser installed from most gunsmiths for about $250-$300
If you want flush cups, rails etc I believe you must install on your own as I didn't see the option when ordering mine.
Seems like a great option for a stock and has a great price point.
Go big tactical currently has a used one for sale with bottom metal for $495. That's a great price
Can also talk to Gary at Big Horn Sales to order new