Hi Steve,
I recently designed one and built a prototype for testing, and performance is very good (much better than VPP).
We plan to make two models... a simple version with 2 gain settings, and cartridge loading via dip switches, and a higher-end version with remote, 2 programmable inputs, and more loading options.
I hope to have the simple version available later this year and we're shooting for a retail price of $600-$700.