(This post was last modified: 08-23-2017, 09:46 PM by charlievarick.
Edit Reason: update
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Thanks for that update, BadDad. Based on today's shave with my Feather AC, I've concluded for now that my favorite AC-style blades are the Feather ProGuard (which let you down, I know, proving, yet again, that YMMV is the only rule that always applies with this stuff) and the Kai MG (Kai Proguard). The Kai and the Feather guard blades are equal, in my view. I get great shaves from both.
For a blade without a guard, my favorite is now the Kai Captain (Blue). I greatly prefer it to the Feather Pro. It doesn't feel quite as smooth but it feels steadier during the shave, more forgiving, and much more like a regular straight. The shave is superb. I'm going to order some Kai Milds from Try a Blade and give them a whirl. Will report back.
Update (14 Aug. 2017). Used the Schick ProLine today in the Feather AC. Very smooth, pretty forgiving. I wasn't knocked out like some have been, but I wasn't using it in a Mongoose-style razor; had I been, I might have been equally impressed. It's a very good blade, I prefer it to the Feather Pro by far, and would put it on par with Kai Captain (blue) blades. I use blades without guards in the Feather AC mostly to improve my technique. When I want to relax and enjoy the shave I go with a guard.
Update (23 Aug. 2017). My face's jury is in. For the Feather AC or DX, or the Kai versions, the Feather ProGuard and the Kai MG (proguard) are equally smooth, equally sharp, equally forgiving, and very long-lasting.
Of the guards without blades, the Kai Captain and the Schick ProLine are equally smooth and sharp. The Kai Captain hasn't nearly the longevity of the guards. I have used the ProLine only four times so far but so far so good. Feather Pros are in third place. They are smooth and sharp but too eager to take a bite. I have to check with my carrier before I use them in a Feather AC, though they're fine and well-behaved in any of the Mongoose-style SE razors I've used, but still not as good as the Kai or Schick for my face.
Am eager to try the Kai Captain Mild, a blade I used to use a few years ago. Would like to try it again and see how it compares.