I use a lot of LEE dies, but I replace the lock rings with narrower rings because there's not a lot of room on a Dillon 550B die plate, and RCBS lock rings work better in that space. For a time, LEE had the best 9mm dies on the market, everyone else's dies oversized the cases and made them look like a coke bottle, but LEE's just did the job without overworking the cases, AND they still fed perfectly well. I had been using RCBS carbide 9mm dies, and after trying that sizer out, I replaced several sizers from RCBS with the LEE stuff. Case life was enhanced, and still no malfunctions.
I used their 9mm taper crimp die on .38 Super cases without a hiccup, too, though it wasn't screwed down as far as it would have been for a 9mm case. The LEE prices were good enough, that I could buy both .44 Mag dies AND .44 Special dies at what one set of RCBS carbide dies cost back then. No more adjusting dies from Spl. to Mag. I did the same with .38 Spl and .357. No issues.
