I got about 4 ounces of this in my order from Ten Ren. I drank it years ago, and I remember it was a strong tea... but at the time I wasn't aware it was green, I thought it was just a black tea.
It makes an excellent cup of tea, especially for the price (3.50 for four ounces). The flavor is stronger than other green teas I drank. One thing I notice about the flavor is that it doesn't have the usual grassy taste I get from some other green teas. So is it really a green tea in the sense the leaves aren't oxidized?
The website says gunpowder is made from older leaves. Also, I have read in one medical study that the older the leaves, usually the more catechins are in the leaf... but old leaves from the grading perspective are considered inferior, and are thus sold cheaper.