Beppu's "tornado hell" geyser - despite what the locals might tell you, this is definitely not Japan's answer to Old Faithful. They've actually handicapped the geyser by building barriers that limit how high it can shoot up, which kind of takes away from the natural wow factor.
Still, it's part of the whole "hell tour" experience in Beppu, and you'll want to get that stamp in your hell-touring book (yes, that's a thing here). While the geyser itself might be a bit underwhelming, especially if you've seen Old Faithful, it erupts pretty frequently - every 30-40 minutes - so at least you won't have to wait long.
Quick tip: don't build this up as some massive natural spectacle in your head. Think of it more as one piece of the larger Beppu hell tour puzzle. And hey, they've got some decent local snacks and an Azalea garden to check out while you wait for the next eruption.