http://vintageking.com/blog/2016/10/u47-shootout/?trk_msg=RTJG3H5FATK4R4C9SKRT2BBQB0&trk_contact=HAVSQPQ9TKI4KAP64QQ4INA8JG&utm_source=Listrak&utm_medium=Email&utm_term=http%3a%2f%2fvintageking.com%2fblog%2f2016%2f10%2fu47-shootout%2f&utm_campaign=Shootout%3a+U47-style+microphones+%2b+The+latest+Vintage+%26+Used!
 

I can definitely notice a difference.  Telefunken nails the 47 sound, just complete relaxed goodness.  The closest to it I think is the Bock. All the others were slightly too edgy and forward.  Slate actually held its own against some of the copies, just a bit gritty by comparison for my taste.  Probably a better deal than buying a U47 clone.  

If I were a studio owner (for hire, which I'm not) I'd be looking at THIS instead of Slate's offering.