They're still out there, as best I know. I have a GP-130, their flagship vertical. For the money, it is a very good piano. It's been the performance value pick of Piano Buyer for many years. My understanding is that they only bring in about 50 of these a year. Their 48" is offered in many more finishes and works pretty well for an average player, especially if you like the sound. The 130 is like a Model T, you can have any color you want, as long as it is black.
George is quite right, this piano can get loud, especially in the bass. My old tech has retired, but the new guy marvels at the sustain and the bass. In his opinion, the bass is as good or better than a six and a half foot grand. The treble is good and after Rick Clark's tuning schedule, the piano holds tune well.
There is a hole behind the music desk and with the lid propped, this piano can generate a wall of sound, almost like laying underneath a grand while somebody plays. Having said that, some pianists will not like this piano, particularly men. It's at its best with a lighter hand, which is why it works really well for my wife. With lighter hands, the piano can be melodious, yet it's like a car with a turbo...Lean into it and things happen.
Build quality is very good for a Chinese factory. There are some things I would change...The only problem the piano has ever had was a plastic fitting on the end of the rod which controls the sustain (and I think that was due to letting someone play it that shouldn't have) broke. The fitting would literally have been on a slow boat from China, so I made one from a shaped dowel rod, drilled it and glued the metal pin in. Piano fixed.
But that problem speaks to modern piano manufacturing with some plastic or synthetic parts. The other, associated problem would be dealer network and parts support for any unique parts. My piano came from Dallas. I think my closest dealer now, may be in Houston.
So, what niche does this piano fit? My opinion...
You have limited space.
You have a limited budget.
You are an average to good pianist, with a lighter hand.
You like the bass of a big vertical, but also need a decent treble with balanced scale.
I think the piano punches above its weight, especially in the right hands.
A few words from Piano Buyer...
https://www.pianobuyer.com/post/staff-picks-recommendations