That was kind, Recped. And I do concur, line that first R4 on the left, watch the approach, and forget about the portage on the right - it's barely there, or so I was told.
When we did it last summer it was up around 330, I think. We had hoped to catch some of the marked beach campsites on Day 1, but they were underwater. I can, however, confirm that there are beaches in those places. What the water level has to be to see them, I don't know.
If you can get to Matagami the night b4, you can catch the hotel there, then it's about 3 hours to the put-in - much less if they've finished some of the paving they were working on last summer. Also remember you'll have daylight til 10 or so. I think we were unloaded and had said goodbye to our vehicle at the putin by about 1pm and got to the tent cabins by 6 or 7pm. We pitched tents outside the cabins which was fine. Not much of a view, but fine. Buggy.
As to the clip of the river, you'll get a sense of it here.
https://www.youtube.com/watch?v=xUZRocYDp_Q Have fun!