It's worked great for me too. This is the best piece of brewing equipment I've bought in awhile.
I don't think I'd use 12 oz of hops in it though. If I ever used that much in one recipe, I'd try maybe 8 oz max in the screen, remove it at knockout, whirlpool the last 4 oz, then use the screen to strain those out on their way into the bucket. Pushing it beyond what it can handle doesn't mean it doesn't work.
My theory on the utilization issue -- because it's definitely unnerving to see how little the wort moves inside the basket -- is that the alpha acids separate from the vegetable material and move throughout the BK. The temps are the same on both sides of the barrier too.
Finally, it's not like anyone just wants to shove a new thing into their BK. I've had a longstanding issue with my hoppier beers having a distinct vegetal note, which has always driven me nuts. For me, this 100% solved that issue. If I have to buy another ounce of hops to get my IBUs back up, so be it. I'll do that gladly.