Diameter and width do different jobs, and it is worth keeping them apart.
Diameter sets how far the deck sits off the surface and how the wheel meets anything that isn't flat — the seam where a quarter meets the flat, the lip of a kicker, the join in a built park. A bigger wheel crosses that kind of edge with less interruption. It also eats a little of the gap between deck and surface, which matters if you run low trucks or a deck with shallow concave and you're already close.
Width is contact. At 6mm these are not narrow, and a wider wheel on a table or a smooth ramp surface gives you more urethane touching the thing you're rolling on. Whether you read that as stable or as draggy depends on your surface and how hard you ride flatground.
Hardness is the number people argue about most and understand least. 70D is what Bloob states; durometer figures only mean something next to a surface and a measurement method, and brands do not all publish either. Compare it to the Bloob 80's by all means. Comparing it across brands is a coin flip.
Bearings are the part that makes this a park-leaning purchase. ABEC-9 wheels roll, which is the point if you're riding transition and carrying speed out of a ramp, and largely beside the point if your setup lives on a desk ledge and a rail.
