Blade choice for me depends on the razor and the amount of growth. I have found face prep can make or break any razor blade combination.
I have tried most of the Feather line of AC blades (Pro, Pro Super, Pro Guard, and Soft Guard) and many of the Kai blades ( Kai Captain Titan Mild, Kai Captain Titan ProTouch MG, Kai Captain Sharpblade, and Kai Captain Blade) as well as the Schick ProLine P-30.
I have used several of these blades in my barber style razors (Kai Captain Standard, Feather SR folding, Feather SR kamisori, CJB GR-100B, and Irving Barber Company shavette) and most of these blades in my safety razors (Against The Tie SE1, Occam's O.R.E.N., Blackland Ti Vector, Razorock Hawk V3, and soon a Mongoose SS).
I would say in general, I found I preferred the Kai blades over the Feather blades as I find them to be smoother blades for my face. Other people love Feather blades, so it is good to get sample blades and see what works for your face for the razors you use.
In the past, tended to favor the Kai Captain Titan Mild blades for the barber razors. For the Ti Vector, I prefer the Kai Captain Titan ProTouch for light growth and the Kai Captain Blade for more efficient shaves. I asked Brad Maggard at Maggard Razors about the future availability of Kai Captain Blades and he had plenty on hand and did not see any issue getting more blades in the future.
I had issues trying to remove a Kai Captain Titan ProTouch MG blade from the Against The Tie SE1 razor head, so I do not use that blade with that razor head. It seems most razor makers focus on the Feather blades as far as blade fit (and maybe specifically the Feather Pro). The Feather Pro Super is a deeper blade and will not fit well in all razors (for example).
I have a several boxes of Feather Pro blades that came from other used razor purchases, so I am always looking for razors that can use them up and give a smooth shave. I don't find the Feather Pro blades to be smooth, so going with less blade exposure/milder razors/less growth seems to be the key for me. For now, I am using the Occam's O.R.E.N. razor with the two dot cap for one to two days growth to work through them.
I read a
post from Shane (
Blackland Razors) stating that the Schick ProLine P-30 blades have slightly narrower hole patterns and can be very inconsistent in their holes (even within the same pack of blades). I have not liked the P-30 in my razors and some of my razors will not load them at all.
Better face prep/varying the lather thickness for different razors and changing out the handles (length wise or weight wise) can also improve your shave.
If you have questions about any of the blades I mentioned, let me know and I will be happy to dig through my notes on those specific blades.