When I first bought a pair of Galibier SuperGuides I was warned to get neoprene sheets and cut them to fit the footprint. The insole of the superGs were beautifully crafted, hard leather. Along with the steel shank you could not have a more perfect conductor of cold from crampons strapped on to them (which is what they were for.) I dutifully used them, and they did cut down on the cold, but I also appreciated the additional cushioning. Fast forward about 35 years and I still like a nice insole, especially with very flat and flattening feet.
(Benjamin Dulchin sporting said Galibier Super Guides in their 3rd decade, somewhere on the Sisters in the Adirondacks I think)
I'm a long time user of Superfeet's green, and orange insoles. I like their new black ones just as much as all I've used. The holes in the forefoot seem like they might breathe better, but I not sure and have used them only in cool and cold weather. The holes do cut some minor amount of weight. Maybe they are supposed to look cool and I’m overthinking it.
Custom orthotics insoles are a luxury and arguably fit your individual feet best. Superfeet does offer a range for high arch/volume, etc. Except for the most specialized custom orthopedic applications, like for very small last ski boots (think Dynafit TLT 5s) or other weird shapes, I'd use these. You can always trim them. I like to buy them to fit, which they do, and well. A good fit is also as warm as that specific boot will ever get. If you have a good fit on your boot you can focus on climbing or skiing as well as you can, whatever that means. Uncomfortable feet generally drive normal folks from the sport by which they experience that discomfort.
Cousin Joseph Hooper after almost stepping out of generously sized boots in the Catskills (Spiral Staircase?)
The liners these sometimes replace are those stock ones included by boot manufacturers who would like to sell you their $600 mountaineering or $900 AT boots. They should put these in there as stock. It's similar to using an Intuition or Paulau moldable ski boot liners (which top manufacturers do include): those who offer a premium boot should include a premium liner. I think these are enough of a mountain standard that manufacturers of high-end boots should make them standard. And I like them in approach and work shoes too.
So the blog title is from a (?) joke. A man in a trench coat walks up to an aged female fellow passenger on the subway platform. He opens the coat and exposes himself to her. She looks at his open coat, then looks up at him and says 'You call that a lining?'