I have owned both over the years, as well as 545SD's (basically an sm57 with a reed on/off switch), and the older ones have sounded more even tempered and less offensive up top to my ears. Shure says that the current production sm57's are the same, but I haven't thought so in the end sound. I think it's probably about on par with how current versions of speaker models don't sound like the old ones. Some people chock it up to age, but I have my doubts there too. But we all have to get on with it, so use whatever is practical.