For glare testing try looking up at a steep angle on a sunny day. I found the toughest test for glare was looking at mountain goats high on craggy cliffs from a lower position in a canyon. Because of my Habicht 8x30 W's poor performance doing this I sold it.
I agree, that's a very good test. Another useful test can be performed when you observe the shady edge of a forest in the evening, when the sun has set but the sky above the forest is still quite bright (Holger Merlitz describes this in his book). This can lead to a sudden loss in contrast even in good binoculars where you would never expect it. As you mention, the (otherwise wonderful, I love it) Habicht does not do very well in this and other straylight / glare tests.


