Reddit reviews Uni Mechanical Pencil Lead, Nano Dia, 0.5mm, HB (U05202NDHB)

This beautiful Uni Mechanical pencil with the "Kurutoga engine." This rotates your lead a few degrees each time you lift the pencil off the paper, which results in an awesome consistent line weight and eliminates the "broad-siding" of the lead. Paired with these fantastic leads and I haven't accidentally broken a lead while writing since September.

Sure! I'll start by saying that my favorite lead is the Uni NanoDia lead, which I've used in both the 0.5 and 0.3 mm sizes. I discovered that I prefer smaller lead sizes (and pen sizes) when I borrowed the pen in my EDC (Uniball signo 0.38mm) from my friend. I have pretty bad handwriting, and switching from a Pilot G2 0.7mm to a smaller pen seemed to help the legibility of my writing, which is why I opted for the smallest GraphGear. I recommend 0.3mm for notes because that's what I prefer, but if you're doing something that needs shading I would surely opt for a larger lead size.

This is kind of a niche add-on, but I work with musical notation a lot, so having a smaller lead allows me to see details in what I've drawn on the staff more easily, which is another reason I choose 0.3. Hope that helped.