Switched back to a GSB after my ill-fated Astra SP shave yesterday, and the S2 was back in full purr this morning.
What a difference a blade makes, David! If you like GSBs, sometime you should try the Gillette Platinums that come in a package with the same blue/white layout as the GSBs.
Funny - blades are one of the most YMMV variables in shaving!