sparring with TDs = the best MMA training?

most amateurs and hobbyists who train do the oldschool bjj then stiking then takedowns at their specific gyms.

however more and more pros seem to be spending more time freestyle sparring with takedowns.

is this the best prep for an MMA fight?  if your goal is pro fighting, should it replace the bulk of your "specialization" training?

I think most classes should end with such sparring-always do for me