At a certain point, chisels are good enough and hold an edge well enough. The quality of the steel is not the only thing that is important. You may want to look at other factors, like:
* Do you prefer one chisel style over another? (The tang vs. socket debate! - save it for another thread.)
* Do you prefer one handle material over another? (Handles are replaceable; some people make their own.)
* Do you prefer a certain handle shape?
* How does it feel in your hand?
* Is it comfortable to use?
* Does it cut easily?
* Does it cut where you want?
* Does it not cut where you don't want?
-> Is it the right size?
Newer chisels are metric size. A typical set might contain 6, 12, 18, and 25 mm wide chisels, despite whatever the label says. Old chisels are mostly genuine Imperial size. A typical set might contain: 1/4, 1/2, 3/4, and 1 inch wide chisels. For many (most?) chisel uses, it doesn't matter, but there are times when the exact width does matter.
In case it matters, I use a 1/2 inch chisel far more than the others combined. It is the right size for many jobs. When I was restoring the old Crown chisels I asked my friends, and every one of them told me that they use a 1/2 inch chisel most of the time and rarely use the other sizes.
I have two nice Crown 174R chisel sets with rosewood handles. One is an old Imperial set and the other is a new Metric set. (Why I have two is a story for another day.) I like the handle shape and the feel of real wood in the hand. They just work for me. I also have a cheap, lousy, Black and Decker 1/2 inch chisel I bought in 1980. I use it the most, even though I prefer the Crown chisels.
The I hate to admit it, but most of the time, I reach for the cheap, lousy, Black and Decker 1/2 inch chisel. It has a plastic handle and does not feel as good in the hand. Despite being a cheap, crappy chisel, it cuts well and stays sharp for a long time. I find that I reach for it most of the time because:
* I am used to reaching for it.
* It is usually ready-to-go sharp and stays sharp longer than you would expect from a cheap chisel.
* It sits in the front of the tool drawer by itself, ready to use. The Crown chisels are sets in the back of the drawer.
* It just works.