Rod,
the delay is audio and video, MC keeps both neatly in sync.
For me the delay was annoying because I wanted to use it for watching Sat TV.
Zapping channels is quite impossible with a delay of 1.5-2 sec.
Basically all the commands that happen at the source will be delayed.
If you can live with these restrictions it should work for you.
I don't use my Colossus anymore because of the delay. I coud sell it to you, were it not that i'm in Europe ;-)
I used the Decklink after that, which has no (hardly) delay, but a crappy driver that doesn't save it's settings.
In the end I gave up on it.
There are other solutions, Mojave is very knowledgable on the subject, not sure he's reading this though.