Definitely the Merkur blade that came with my 34c is the worst. I take the point that was made that early DE technique may color one's initial perception, but I would still argue that Merkur makes a pretty lousy blade.
The Merkur blade that came with my razor was horrible. Super-Max Platinum was horrible too. They are tied for the worst.
Personna lab blues ... I really really want to like them. I've gone back and revisited them a couple of time. But they just don't work for me.
This is what I'd expect to read from just about anyone who's been using a DE for awhile. About a year ago, I started a revisit thread for blades. While some blades didn't feel great, I could get DFS with all I tried. The test kinda petered out swiftly. Some of my least favorites at the time were Derby, Bic, Shark, Lord, and Indian Gillette
28 blades into my test. There are two tied for the worst: Merkur Platinum and Asco (red label). There are three more that I ranked as poor but better than the two already mentioned. They are Personna Platinum, Crystal (by Personna), and Derby Extra. These are just not good blades - at least for my face and my razor (Merkur 34c).
Derby and Merkur are the standout worst for me, that I can remember. Honestly though, other than the occasional odd blade, the only blades I've used for the last 5 years are so are Viking Sword, Astra SP and Ladas.
Never tried the Viking. However the Astra SP and Ladas are among my top 5 and will be in the bulk order coming up.
Razors and blades form a system. Blades like Personna and Derby Extra are not sharp enough for the mild geometry of a 34C.
Astra SP - I cannot get on with them. Derby's I like though, they don't last long but I always get a good and comfortable shave. Isn't it strange that blades work differently with each person.
I generally agree. When I first started there were some blades I didn't like. Now I can get a DFS from just about any blade...with one exception -- Merkur. I don't get it...how can a company that makes such great razors make a blade that is so un-smooth and jagged feeling?
Since Solingen is literally the sharpest city in the world. " City of blades" and probably a hell of a lot missing digits, I agree and always wondered why Merkur didn't make a blade as good as their razors. Might just be the steel used is thread like, more so than other tempers and they pride themselves on their steel. Merkur blades are not for me, and neither are Wilkinson, which are made there, or at least were.