I'm not sure about award stays, but they are pretty consistent on paid stays. I was there again a few weeks ago and I think I got the same Executive suite upgraded room as I got the previous time. I very much like this IC, except of course for the parking fee.
I would give them a call to ask about award treatment and if they are stingy, maybe switch to an HI. There are lots of choices all over LA county so pick the one that suits you. The HIX Century City is right near the IC and not too bad.