Personally I'd make the monitors the same size as real monitors. So... yeah maybe they'd be HD if they took up 2/3rds of peripheral vision, which would match my current monitors. But you could also have more of them, and handwave them away when you want the table back

And when on the move would be better than... nothing, which is what it's competing against. Look at phones, they're absolutely abysmal for both input and output. But they're mobile. Laptops? They're not as good as desktops.... but they're mobile. Virtual displays? They're mobile, allowing more bandwidth in, it's going to be good