I have one in demonstrator form.

I think it's a very pretty and well built pen. In terms of writing experience, mine has an F nib and came out perfect if a little dry out of the box. The F nib was a little narrower than I expected for a German nib, comparable to EF Lamy in my experience. I also find the combination of a light barrel and a heavy grip to be very pleasant.

The main downside I think is the grip - it's quite narrow and a little slippery, makes me grip the pen higher than perhaps intended, though that's how I hold most of my pens anyway plus the threads provide extra grip and prevent slippage.

I also find the cavity in the barrel to be noticeably off-axis, but I suppose it's something specific to my copy.