I was in the area and decided to give this place a try. I've never had bingsu before so I don't have anything to compare it to.
I came on a Wednesday afternoon and some of the seats were filled but there were a lot of tables with leftover bowls and cups that were sitting there for who knows how long. There were three employees behind the counter that didn't look busy at all.
My bf and I sat beside the counter and it was a good spot because we were able to see the bingsu being prepared which looked pretty cool. I ordered the mango bingsu to share with my bf. The shaved ice on its own wasn't sweet or bland but I wouldn't eat it on its own. The mango pieces and ice cream definitely "boosted" the overall flavour and the dessert as a whole is pleasant. My only complaint is that the mango chunks weren't peeled properly prior so chopping it up so half the time the mango tasted slightly bitter because the skin is still intact.
Overall it was a decent experience. The weather is getting cooler so I probably won't return until the summer.