First off, you have razors with 4 blades. That is like pulling a lawn mower across your face. And for me, and my head? I have tried both of them long ago, and they both dug furrows in my scalp. I am talking trenches you could have planted corn in. Not good.
I use the Schick Xtreme disposable. Why disposable? Because they cost less than the replacement blades. Period.
That is all that needs to be said about that. Because when you shave your head and your face on a daily basis, you ARE the expert as to which blade to use.
Take note of that Schick Corporation. Unsolicited praise.
You are welcome.