Yep, binoculars have to be tested side-by-side, because magnification plays a definite role in perceived brightness and sharpness. There aren't very many variable-magnification binoculars out there, and most aren't all that good. So I compare binoculars to the best of each basic size I have on hand, which are usually very good.
The 8x30 MM30 held up pretty well against a Swarovski EL 8x32. The Steiner wasn't as bright, but was very close in sharpness. Also, many of the Steiners have "wings" on the eyecups to block out side-light, which brightens the view considerably. With the wings out, the Steiner was very close to the Swarovski in brightness as well.
On the down side, the wings prevent using glasses. If you wear glasses and take them off to use the Steiner with the wings, it has to be refocused, which is more difficult with IF.
