While I think something like this makes sense, the pricing seems off. For $600 you can build a PC with a desktop GPU. If you want to make it easy to set up, you could just use an off the shelf mini-PC and preinstall everything so a non-technical user can get started without any hassle. I really hope we’ll see more Steam machine like devices in the future.
Maybe they’ve finally fixed those problems. In Lakka, I set my controller up once (for each unique controller) in RetroArch frontend, and then it works in any emulator core. I don’t think it’s normal to have to set up the controller in each core (but you can, if you want or need to!)