Hey, Fuzz. Looks really nice.
I don't know if you read my review on that monitor (well, its little brother), but I mention setting the HDMI Black Level from "low" to "normal" based on an online review that I'd read. I don't know if that would have anything to do with the brightness issue that you mentioned. You may need to go through a procedure to get your Mac to recognize it as a monitor and not a TV, and if so, check out the site
here for the instructions that I followed to get that working on mine.