You cannot compare Dan, Efty and Epik
They are each unique....
Dan - is the best marketplace but it will cost you an arm and a leg.
Efty - is the best self hosted marketplace (well as close to self hosted as you can get for a small fee)
Epik - is a registrar and for security and escrow (escrowish) service they cannot be beat. I guess they have a marketplace but it has a long way to go before it catches up to Dan or Efty, but it's free so you have to decide.
So you see.... each is kind of unique and if I were a betting man I would say that Epik will eventually knock it out of the park. When all the different services Epik has get streamlined into one dashboard, or the marketplace gets a shiny facelift they will be the clear winner.