I have the Lee dies marked .38 Spl and reload both. The instructions with the dies say something about turning the dies more for .357 (I'm usually loading .38). I've had no problems with the dies. I did find that at least with this caliber, seat the bullet and crimp in two separate steps to avoid crushing cases and bullets from trying to combine both.
FWIW, I also bought the Lee factory crimp die for 38/357 and am now using it, but I don't think it works any better than the crimping shoulder on the seater die. I use it because I have the Lee breech-lock bushing system, and having a separate crimp die lets me leave all four dies adjusted properly for .38 Spl without adjusting for each reloading session. You could get the same result by buying a spare seater die (or the non-FCD "improved crimp die).