I own two different gmmk keyboards, and I can say that they are the best thing ever happened in this hobbyst world in the last years.
They're a joy to use, they're programmable, and quite high quality. The 100% keyboard, unlike the smaller ones, has a fixed cable; this is the only thing that I would change.
I they ever make a cnc solid keyboard, compatible with some of the existing pcbs, they will put out of business 99% of the hobbist vendors.