I purchased these blades from West Cost about a month ago, and have been using them for 2 weeks. My favorite until now was the Feather Hi-Stainless, but these may actually work better for me for less cost. I'm getting the same number of uses from these as the Hi-Stainless. I use a Merkur Progress, and found that I get a superior shave (just as close, with less irritation) if I set my dial to 4.5.
I have been wet shaving for about 5 years.
Note, I cannot comment on how well these blades work on my jawline and chin, as I have a beard and only shave my upper-cheeks and neck.
I really don't have anything bad to say about these blades. They are high quality. They are sharp. They shave very well. I'm happy.
I will add that motivating factors for me trying them was:
1. Made in the USA.
2. Packaging. I am trying to be conscientious about plastic and waste and I was not happy about throwing away a small hard plastic box every time I used 5 blades. These blades show up, in bulk, individually wrapped and in a paper box. Simple. Personna probably did this for cost-cutting measures and not for the environment, but I wish other blade manufacturers would take note. I really do not need a disposable plastic box with every set of blades. It's wasteful.
I recommend giving these a try.