Let's talk safety razor blades!

Here are the brands that I've tried.

• Shark Super Chrome: I thought these blades were pretty good, but the quality control was spotty. I used these for a while in my Merkur 180. The quality control was spotty, and I'd get some really good shaves and some poor shaves. Some of the blades lasted a week, some lasted three days, and some gave me a poor shave right off the bat. I haven't tried these in my slant bar razor. 
• Feather Hi-Stainless: These blades are SHARP! I cut myself regularly with them in my Merkur 180. It's easy to do if you're not careful. Sometimes they gave me random nicks, it seemed like. These are not very forgiving. I also tried one in my Merkur Slant Bar razor. I got a good shave in that razor. 
• Gillette 7 O'Clock Super Platinum: These blades are really good. They seem to be as sharp as the Feathers, I didn't nick myself with them at all. I used them in my Merkur Slant Bar and got a really good shave. They seem to last a week. 
• Astra Superior Platinum: These blades are great in my Slant Bar. I get a good, consistent shave. They are also about ten cents each on Amazon which is a major plus! For that money, they're a bargain even if some of the blades have quality control issues. 
• 7 Am. Ugh. Stay Away. These were horrible. I could barely make it through one shave! 
• Crystal Double Edge Razor Blades: I have a thick beard, and these didn't seem to cut it very well. I'd rate them as mediocre, not too bad, but I didn't find them as good as the 7 O'Clocks or the Astras. 

My recommendation is to try out razor blades and find the one that works best for your combination of shaving ingredients. Avoid the 7 Am blades for sure. I'd also avoid the Feathers until you have practice.