iPad as display for Mini?

[crashwins]

I'm confident this has been posted before, but I'm wondering if anyone has found a lag-free solution for this? I'm guessing any kind of connector is out of the question (Apple!). I've seen the video for the ad-hoc connection, but that also looks laggy, no? And with this connection you can't use Wifi it seems. I'd love to use this as my mobile setup when necessary. Thanks for reading!