I'm allergic to something in Astra SP's, so that's that as far as I'm concerned!
Feather.
Value for money: seven smooth shaves out of each blade.
Voskhods are my one & only 'go-to' blade.
I found this blade to be 'awesome', forgiving and perfect with no pulling or tugging, very, very smooth, no irritation and/or razor burn that %99.9 of the time results in CCS's in 3 passes (WTG, CTG & ATG),...and are very compatible with all my razors.