I haven't tried the Pearl Flexi, but I have found the Astra Blue blades to be a bit on the rough side, though some people rate them highly. I'd suggest trying something like a Gillette Minora, German Wilkie or Gillette 7 O'Clock SharpEdge Yellow. Not necessarily in that order though.
Brush: TroyTools - Honey Pearl (2 Band Badger).
Soap: Razorock Black Label
Razor: Pearl Flexi (4/3/1)
Blade: Astra Blue.
Post-shave: Nivea Sensitive Balm.
Oh man that was a rough shave and my neck is red. Can someone help me identify what qualities about the pearl flexi might be causing this for me? Blade gap, exposure, geometry? I was trying hard to focus on my technique with it by making adjustments in pressure and angle, but couldn't get it to feel nice on the skin. For reference I normally use the 6C on setting #4 which is a joy, and can use up to setting 9 on the gillette slim and while that certainly requires more concentration for me and I wouldn't do more than 1 pass on it, it doesn't feel rough/stingy like the flexi does. Setting #1 on the pearl flexi is perhaps the only setting where I don't feel the sting.
I wouldn't say I have the experience to identify exact shave qualities about the razor other than how I feel during and after, but if someone who has tried the flexi and perhaps the others and knows the subtle differences could chime in, I would greatly appreciate that
Otherwise, maybe you need to lift the handle of your razor away from your face so as to present a closer angle of blade to skin.