You can go to Flamingo newsgroup and obtain some special solution as well, frankly speaking, I'm waiting for the official release as well, as the rendering principle is truly amazing and close to reality....for the grains...you can say it's close to high ISO films....
I've tried it for a couple days, the grain is pretty unacceptable when rendering time is limited, but what attract me is the choice between inputing rendering time and sampling, so that you can actually limit the time spend on it.
The beta ver would be far better on rendering speed by 400%, I'll wait for that and give it a shot.
Yet, Maxwell didn't work when I render it in 4Kx3K px, dunno if it's my problem.
The beta verion is released, but there are still many bugs, especially to Rhino (OMG), material cannot be applied at all if you wanna run the rendering. Next Limit (NL) is gonna to upload the patch to fix the problem in these couple days.
In the mean time I'm running some comparison test on the time consumption. A challege to my office computer to keep running for several days.