finally found someone who has a pair of steiner nighthunter 8x30. anyone got an idea of their low light performance vs a similar quality 8x40 roof prism bino?

Ozy
I have had one since they first came out.  Back then they were the best at that price in low light and great for glassing where an 8x30 was good.  No comparison to a Swarovski 8x42, but if you can't afford the Swarovski (like me) I think they are a great compromise.  I do like 'em better then the predator model since most game where I hunt are moving in the morning and late afternoon.  I guess that's why they are the night hunter model.  One downfall compared to other roof prisms, is that since they are auto focus, if it keys in on brush before the animal, the animal appears fuzzy.  With a regular roof prism that allows you to focus them, this won't happen.  Hope this helps.

i've never had any trouble with focusing at any range with the steiners, except closer than say 10m. it's one reason i love them. my eyes do all the focusing. just like if you look at a far object then suddenly look at your hand in front of your face. i find conventional focus systems really annoying because when looking around at different distances you are constantly refocusing and your eyes spend more time looking at unfocused images than with the steiner autofocus system. just my experience. i'm definately out of the swarovski/leica league. just want to make sure i'm not losing lots of low light performance compared to say a leupold, nikon, bushnell or the like in 8x40.