Can't speak to the price, nor the size (I was looking at 7 footers) BUT.......
Grotrian-Steinweg (just Grotrian when sold in the US) was the original partnership between Steinweg (who later founded Steinway and Sons) and Grotrian, who stayed in Gernany.
Beautiful pianos. Was on my short list - really close second to what I got. They have a slightly heavier touch than most of the high end pianos, which you may or may not like, depending on taste.
Really powerful piano, especially in the tenor and bass. If the Grotrian was a car, it would be a Dodge Viper. Really fun to play, deep clear sound. I had difficulty find a dealer who carried any number of them, so I ended up flying to Denver to check them out (I am in Portland, Oregon, USA).
They are highly rated by Larry Fine in his Piano Book, which you might get as a reference.