My wife got me this Hongdian 1851 for Christmas last year, along with the astronaut pen holder. Since I keep it out on my desk, it is the pen that I reach for most often. It has the finest line of all of my pens and I keep it inked up with iroshizuku murasaki-shikibu, which is an incredibly close match to the body of the pen. It has a lot of feedback without being scratchy, and is great to write with.
The calculator is a Casio fx-260 Solar II, which Kristi also got me for Christmas some years ago. It's the calculator that I grab most often since it is the easiest to get to. It's my little Apocalypse Calculator since it has no battery and is solar powered only.
I've been looking at that pen thanks to your post and I have two questions.
I'm not sure about a European distributor, but I can tell you that mine, from Amazon, has a nib that looks like the one that you've found on Aliexpress. I don't know if there's a difference between them. The Forest Rainbow that I have has an anodized nib that probably started off all silver, but both of them are extremely fine, and wrote beautifully right out of the box.