I've made tests with an Alienware m18x R2 via usb3 and with a Lenovo T410 office computer via usb2.
The performance on each of the systems was really impressive. I would guess a delay of 2-3 fps with any tested input resolution.
In my test I captured another notebook which was playing a speech of a politician >> Watching the captured stream with Resolume and listened to the audio directly out of the captured notebook. Lip-synchronisation was okay.
..don't forget...it's a VJ Software and not a Hardware Encore video mixer. As somebody mentioned before - "It's almost impossible to get under 2 fps delay". I would sign that!