This is a very controversial subject. I feel all breeders today are producing much better hackle than we were 10 years ago. In fact I find we are improving dry quality each year. Our barbs are actually getting a bit stiffer and more uniform each year. Our barb count is getting a bit higher each breeding season. When I took our flock over 14 years ago, 80 barbs per inch was about our average across the color families. Today our black family (Natural Black, Gold badger & Silver Badger are tops with the average over 93 barbs par inch and extremely stiff, some even higher. This is a bit higher than the Grizzly family today Hap.
I have improved the stem quality over what it was when I obtained the flock.
We have worked hard to increase the skeleton size on all families which gives us a larger skin and that relates to a higher hackle count.
The feed I have set up for my flock is specially blended, pointing at feather production, not meat & eggs. This is my own formula and I am sure other breeders do the same.
Different breeders grade differently. We all agree that it is in the number of flies that could be expected to be tied from each cape or saddle that if all else is equal, will place the grade, either Olympic medal, or old fashioned grade 1 to 3.
It used to be the best dry fly quality was graded highest and on down the line. All grades are better dry fly quality today than yesterday for all breeders.
We (Conranch) produce no low grade hackle in any grade. I find a grade #3 cape in our hackle is as good dry fly quality as a grade #1. Just because you choose to buy a top grade cape does not mean that it will be a better dry fly quality than if you had purchased a grade 3.
We keep no large inventory so our hackle is all fresh. Hackle does tend to deteriate over time especially if it is laid out in direct sunlight or displayed in a shop, perhaps some sunlight at different times of the day. This is the reason most fly shops tend to display hackle away from windows. It all needs to be protected from infestation of bugs and pets.
One of my most prized pieces of hackle is a very old saddle, that has the grade#1 stenciled on the back of the piece of felt stiched to the back many years ago when it was top of the line. I get it out once in a while to look at it. Sadly today it would not even make a grade #3. Today I would reject it to be burned as not acceptable. As a collectors item it is priceless to me today. It was the best a tier could buy many years ago.

There is way more to grading than I am willing to take time to relate here.
My suggestion to all tiers is to obtain which ever "Brand" you feel is best for your tying and fishing.
For old hackle I suggest caution in buying. There is a lot of Old, poor quality dry fly hackle from gone out of business sales. Brokers trying to make a buck from tiers. If you buy some and like it, consider yourself very lucky. Most new hackle will give you many hours of pleasure in your tying and fishing.
Of course everyone that ties has an opinion on Hackle and grading. Each is entitled to that opinion and I would be the last one to try and change your mind.
I suggest a tier to find a hackle supplier that treats you with good customer service, is honest with you and provides you with hackle you enjoy tying with. If you find you are having problems tying with a particular piece of hackle you may just have a poor piece. Above all else, tying is not as difficult as some would try and lead you to believe. Enjoy tying, keep it fun.
I enjoy tying and fishing and I do hope all of you do also.
Denny, Owner of Conranch Hackle
Sponsor here on FAOL for about 10 years.