I've had Grand Piano Home for a while. They were the only floor standing speakers in the Home line. While I liked them on Jazz and more smaller scale music, I traded them in because of weak, to my ears, midrange. You can find my review on the other AA forum.

Concerto were basically top portion of the Grand Piano, I would get them with a sub for a full range sound or by themselves for a small office system. Definitely amazing finish and a delicate sound. i.e. a proper Sonus Faber. :)

I currently own a pair of the Grand Piano Home, and the Concerto Home speakers, and have for almost 20 years. I have not heard the Concerto Grand Pianos, which I believe were an earlier model to the GP Home.
I have traveled up the SF line to the Amati Homage, and I'm currently the proud owner of a pair of Stradivaris. That being said, I still own my monitor Concertos, and my GP Homes, and have no intention of ever selling them. I find them to very enjoyable to listen to. No matter what I play through them, or how poorly some tracks may be recorded, they always bring a smile to my face.
My apologies if you were looking for a more technical review, or a direct comparison of the 2 models, but I have a deep emotional attachment to the GP Home speakers, and if I were looking for a used pair of speakers in the $1,500 range,(I'm guessing) they would be at the top of my list. Best of luck.

I had a used pair of the SF Grand Piano Domus which I believe we’re one step up from the Home. I really enjoyed them. I only sold them because I made a pretty significant move up in speakers.