This was the first authentic longjing I've ever had, so take that for what it's worth.
I brewed in a 100ml gaiwan with about 4-5g at 175F for about 10 seconds. Especially in the first two steeps, the rich umami with a fresh grassy aftertaste hits you immediately, and I noticed the strength quite quickly. This remained for the second steep, starting to sweeten but lighten out past steep 3.
I also brewed it many times in a tall 13oz glass. Brewed this way, I used the same 175F for the first steep, gradually brewing it hotter (185F+) after the second steep.
It was very consistently sweet this way, with only a reminder of the fresh green.
I would say overall it's quite good, (as I have literally nothing to compare this to lol) 8/10