When I bought my second hand reloading setup, it was completely RCBS equipment. Which is ok, because I got a lot of expensive equipment for $150. All of my die sets were 3pc RCBS, 9mm, 45acp, 38spl, and 357mag.
When loading 38/357 using the built in roll crimp, the RCBS die would always 'chew' up the mouth of my cases. It would sheer off hair like strands of brass every loading and I knew it had to be weakening my case mouths.
Eventually I got into loading 44mag, something I didn't already have dies for. So I ordered the 4pc Lee die set which comes with the FCD. I was going to get RCBS because I was impressed with the quality, but just didn't want to spend the extra compared to the cost of the Lee set with FCD. So the Lee set is what I got.
After using the Lee dies, they are definitely cheaper than the older RCBS sets I have, but they work just fine. The biggest plus was the FCD. It easily and perfectly roll crimps for me without issue. No chewing my case mouths up, no sheering brass off. I was really impressed with the FCD. So much so, that I went and purchased just the FCD for 38/357.
Now, I load my 38/357 using my normal RCBS dies, but I only use the seater/crimper die for seating and use the FCD as the final step for crimping. No more buggered case mouths.
I may not be a complete fan of Lee, but their FCD can definitely be worthwhile. I will probably always use one from now on.