I have fired many thousands of Missouri Bullet Hy Tech coated bullets, mostly in .38 caliber 158 grain. But, also .44s and .45 Colt. They are great folks and run a very nice business.
Coated bullets are much cleaner to reload, cleaner to shoot, with virtually no lube smoke (great in indoor ranges) and easier to clean the gun. Frankly, in my experience, they are slightly less accurate than jacketed, or regular lubed lead. Not so much as to make a big deal at pistol ranges. It could very well be my reloading technique. I don't know. Not enough to keep me from buying them though. I just bought 4000 more of them in .38 and .44!
I have never seen a good, thorough comparative study of their accuracy and would like to see one.
I once shot three different guns, on three different range days, comparing 158 grain coated bullets against Federal 130 grain jacketed factory ammo, on a PPC type course shooting up to 25 yards. The coated bullets gave me a larger group and lower score than did the 130 grain ammo. It still could have been my shooting, and definitely not a scientific comparisoin. Still not enough to keep me from getting more.