mechanism and design of the newer hidden clasps are better than the classic folding clasp. I remember video of a NASCAR driver having a crash and as the windshield shattered and his arms flew foward, you could see the bracelet of his Day Date pop open from the g Forces and the watch went sailing out the hole that used to be the windshield.
My impression is that the steel/metal bracelet was the response to complaints about leather straps getting sweaty and stained and rotting and causing rashes, etc. In WW2 steel was too valuable and the military tried simple canvas straps on their watches. Today the metal "tool" bracelet have been replaced with nylon and Velcro. I must say I go back and forth between leather and metal...and I'm sorry I sold all my 18k bracelets because it will cost me twice as much as I got for them to buy another.
Years ago I had a DateJust with a folded metal bracelet and didn't like it...now I have gone 180 degrees and it is my favorite style of steel bracelet.
But is there any data about which style...D link or folded...has a history of less stretch, fewer failures, etc.?