I don't have any solid proof--just what I've read here in terms of experiences and photographs of different logos. In my personal experience, vintage Blacks are very smooth (unless used and have dirt inside, then you clean them out, and they are smooth again). The only brand new Blacks I've used happened to be very scratchy, so I can't call it a good sampling of new Black switches. By scratchy and gritty I mean like you could feel scratchy resistance and you could hear the scratchy sound. Same with Brown switches, which are tactile, and I've tried like 10 or more different keyboards with Browns by now between me and my acquaintance, so I can tell the difference really well.
Now, switches do smooth out with use. But if you look at completely brand new or barely used keyboards, there can still be a variation among modern batches. So far, I have experienced VERY scratchy browns on 2 different CM Storm Triggers (one was mine, the other was from my acquaintance). I got mine brand new, and his was barely used as well. When I was trying out my acquaintance's keyboards, after my Trigger, that's when it hit me how dramatic the difference in feel between different Browns was. When my Ducky came (brand new), those Browns started out very smooth right away. I got a used Filco with Browns from someone, and that one was quite worn in after a couple years of use, and the switches were buttery smooth. My pink Filco was barely used and had pretty smooth Browns right away (not quite as buttery smooth as a well used one, but nice still).
MX Clears--a different switch. I got a sample of 4 used Clears from a kind member here and tried them with different springs, when I was deciding on my future keyboard mod. I then got 85 brand new Clears, and I could tell the difference immediately. That scratchy feeling and sound were there, but not as prominently as on my very scratchy Blacks and Browns. That feeling DID NOT go away after proper lubrication. It was diminished, but the switches are still not as smooth and quiet as the used Clears I got. Also have Clears now in a lightly-used Ducky Shine keyboard I got for my OH, and those are pretty smooth, not that much friction (unlubricated).
So in summary of my personal conclusions, here are some of the likely possibilities:
* Switches have different degrees of smoothness straight from a factory. So batch-to-batch variation.
* Switches smooth out with regular use (understandably)
* You can help the smoothness by lubricating the stems--but only to some degree. Mechanical wear is still very important.
* vintage Blacks I've tried are almost all very smooth, some super smooth--before any lubrication. It could be from repeated use or it could be those "smooth" batches; perhaps a difference in plastic composition or tooling.
