I bought a 100 pack of Astra SPs a couple years ago and been using them ever since. They perform reasonably, but I was looking for a baby shave with less passes. Then I decided to give others a try. I bought two of each blade and conducted my trials methodically. I put each in two razors: Merkur 34C and Razorock DE1. Marked one side, so I only used each side once. Shaved two days apart every time. Basically, I tried to limit bias as much as possible. Anyway, here are my thoughts (ranked). They may surprise you.
Lord Platinum - A little smoother and more efficient than the Lord SS. Good shave.
Gillette Nacet - Similar to Astra. More expensive however.
Perma-Sharp - Not too different from Astra either.
Lord Classic SS - Average all around
Personna Lab Blue - Many nicks. Didn't get the closest shave with it. I was hoping for a BBS.
Gillette 7 O'Clock SharpEdge (Yellow) - Started out pretty sharp, dulled quickly after first use. Several nicks.
Croma Diamont - Scrapey...not comfortable. Nicks galore.
The one blade I forgot to get was KAI. I don't know if it's worth the hype and double the cost of other blades.
Lord Platinum - A little smoother and more efficient than the Lord SS. Good shave.
Gillette Nacet - Similar to Astra. More expensive however.
Perma-Sharp - Not too different from Astra either.
Lord Classic SS - Average all around
Personna Lab Blue - Many nicks. Didn't get the closest shave with it. I was hoping for a BBS.
Gillette 7 O'Clock SharpEdge (Yellow) - Started out pretty sharp, dulled quickly after first use. Several nicks.
Croma Diamont - Scrapey...not comfortable. Nicks galore.
The one blade I forgot to get was KAI. I don't know if it's worth the hype and double the cost of other blades.