Quality is always a touchy subject on the other bulletin boards. I will tell you what I know from what I have seen.
Quality depends on what you're looking for in a hat.
What I look for is a soft hat that won’t slouch after rain and won’t shrink. All modern hats shrink, vintage hats from what have seen do not. According to a couple of the hatters I have spoken to, they have no clue what the process old felt makers used was that kept the felts from shrinking.
First of all you will hear many makers talk about content and how a 100% beaver is the best you can buy. What I am going to say is very controversial on some forums. Beaver is not always the best material for a felt hat. It depends on the quality of the fur used whether it is hare, nutria or beaver. There are different qualities to the fur of all the animals.
For a stiff hat like that you'd see on the plains of Texas, nothing beats a 100% beaver felt hat. The hat is shellacked stiff and can take the rain without flinching. The set back is that 100% beaver hats do not usually make good soft hats you’ll see more about this as you read further.
For a fedora which is meant to be a soft hat, the felt you are looking for is usually a blend. Blending a beaver fur with a nutria or hare fur allows the hat to be malleable without losing integrity. If the hat has a good memory and a felt hat can be bent and squished, it will not end up cracking easily at points where you are putting heavy stress.
With felt not meant to be soft, or for stiff hats, you quickly get what I call the grocery bag effect. The felt breaks down at the areas where creased. This is obviously more apparent with thick stiff hats Like Akubras or Cowboy hats, though if you have the wrong soft dress hat made of bad materials (like I said it is all about the fur used) you can ruin it off the bat and have a hole in a few months.
You need to remember too that some hats just aren't meant to be squished or floppy. Some hats are work hats that need to be stiff to hold up against the elements, and that is why there are different types of hats.
Below are pictures of my Graphite colored Optimo.
I treat my Graphite like a red headed step child. It's taken the abuse for about a year now and this half beaver and half nutria blend doesn't slouch in the rain like all my other modern brand hats have. It gets softer and softer... to me that is a benefit. I've seen Optimo take flak for their light weight hats because they are very very floppy. Optimo does make a heavy weight hat too.
Light weight hats have their place and the demand for them is strong.
I actually preffer lightweight over heavyweight.
Borsalino
I have seen several modern Borsalinos over the past few years and have owned two. Both were ruined by light rain. There is no density to their felt when compared to quality hats and the two I owned literally acted like cardboard in the rain. They may have had a reputation for quality, though that reputation is no longer valid. Within the first week I noticed that fur was just coming off the hat, very loose felt. The color is also topical and not all the way through the felt. So my grey hat after a few wearing started looking brown at points where the felt flexed. They have a roll up model which from what I hear does not come back to it’s original shape without a few problems. The construction of the hats is sub par.
Herbert Johnson
I owned two modern Herbert Johnson hats and I returned one because I was upset with the service. I believe they use an all hare felt though it is not of the highest quality. Their hats will slouch over time. The felt is dense, though cannot be rolled. The construction of the hats is sub par.
Stetson
Better than Borsalino by a long shot. The felt quality is luck of the draw as the density and thickness of their dress hats is all over the place. They ad a lot of powder to their felt to even out the color, so if worn in the rain beware the dripping color. They shrink pretty fast and the name has been driven into the ground by the current owners.
Lock Hatters
I haven’t seen a modern Lock felt hat in person, I own a couple eight piece caps. I have had a few friends go overseas to England and to Lock hatters. From what I hear they are a step above Herbert Johnson. I’ll find out more.
Gelot in Paris
Junk.
The hats I have owned from hatters like Gary White and Worth and Worth were upsetting to me as they did not last more than a year without gaining a hole in their crown. I know that I am supposed to grab by the brim, though I am a rule breaker. I want my hats to take what I dish out.
Optimo hats so far has the best product I have seen on the market. The felt is the closest I have seen to vintage. Very dense and very malleable, I have seen no cracks or sagging in the hats even with the most horrendous of punishment. They do have the Persian flaw of shrinking over time, though with blocking by a competent hatter you should have no problem wearing their hats for decades.
Another plus for Optimo is that the hatter, Graham, is truly passionate about hats and the materials used in them, unlike most hatters I meet. Graham’s hats still have the liners stitched in and the bows have a hidden stitch. The first time I saw one of his hats I thought it was vintage and was surprised to find out it was modern.