I think paydirect is somewhat old now.
I have seen it for atleast 2 years? Dont hold me to that.
Cant remember why I decided not to use it.
Maybe it required to much effort, installing, both parties need it,
extra step and I dont want to lose customers. But I cant remember for sure.
Even if your customer is not a paypal member - the process to sign up and pay is pretty seamless with paypal.
I use 2checkout also.