Going from Project Phono to DV P75 or Gram Slee

If I go from a Project Phono Box to a Dynavector P75 or Gram Slee ($500 to $900 range of phono stages), will I see that much improvement? I do notice that the Dynavector has 8db more in gain for MM cartridge. Wondering how much easier that will be on my amp. I do like the Dynavector cartridges (or similar) and plan to try a low ouput MC in a year or so.

System is Prologue II/Rega P5/Dynvector 20XH.