I started using Nyclads back when S&W came out with them. My usual CCW at the time was either a Colt DS or a S&W M60 and 158 gr. LSWCHPs loaded to +P specs. These were the "best" load that was available until then for the .38 Spl. that were made commercially in terms of reliable terminal performance. Even those were "iffy" in terms of expansion in many snubbies.
They were also pretty rough on the gun if one insisted on practicing a lot with your carry load. Neither revolver was rated for +P use at the time, so it could get expensive to keep them up, as the warranty didn't apply.
Smith came out with the 125 gr. Nyclad "Chief's Special" load expressly to address this problem. Up until then there were no HPs loaded to standard SAAMI pressure specs for the .38 Spl. that would expand reliably at the velocity ranges obtainable from a snubbie. This one did.
When I got caught up in the "Wonder Nine" hoopla and went to a compact 9x19 for carry (it took a while, as ambi safeties from the factory were still rare and I'm a southpaw) my own quasi-scientific testing convinced me that the 124 gr. Nyclad offered the best combination of reliability in feeding and positive expansion in my pistol of the commonly available factory loads.
IMHO, it was and is a great concept that worked remarkably well in practice. Why exactly it never "took off" as well as I thought it should've I'll probably never completely understand. Too many variables for my mathematically-challenged self to juggle at one time, no doubt.
Like George, I bought as much of it as I could locate and afford when I heard that it was being discontinued. I still have a dwindling supply of 124 gr. 9x19, 125 gr. standard and 158 gr. +P .38 Spl.s, and I'm hoarding it like a miser.
ing MORON 
