I have the standard 6 chisel box set and am very happy with them. They took very little work to get sharp and hold an edge well. I would guess that the premium set could only be better. I like the metric sizing too, a 6mm chisel doesn't get stuck in a 1/4" groove.
I also have the 6 piece boxed set and am extremely happy with them. They sharpened up on the WorkSharp 3000 easily and I've been using them to cut and clean the Mortises and Tenons for the Maple workbench I'm building.
They do hold an edge very well and sharpen easily, cut precisely. Everything I want in a chisel.
The premium ones might be better, but I'm happy with these.