I shaved with a Feather blade once...and only once. I was about 6 months into DE shaving, using my open comb Merkur 25c. I thought I had my technique down. I was ready for the venerable Feather blade. It left me battered, bloody, burned and crying in the tub. I have never had a more painful shaving experience and my face has never hurt so bad. I had to go an entire week before I could shave again. It was a full 3 weeks before all the irritation on my neck cleared up completely.
I love both blades. I have to admit using the Astra SP a bit more than the Feather (and the Voskhod more than either) due to its predictability in a number of different razors. That being said, I appreciate the Feather's ability to mow down whiskers and also force me to pay close attention lest I slip and end up with a nick or weeper!
I have only tried a hand full of blades, so far Astra SP are my go to. I just ordered another sample pack off Amazon, so I will have a few more under my belt.