Paradise and heaven are different manifestations of the same blessed life.
The difference is that in paradise one has a body, while in heaven he exists as pure love.
Paradise is the perfection of active life: beauty of the body, gracefulness of motion, effortless power over nature, guilt-free physical pleasures.
Heaven is the perfection of speculative life: one contemplates the mysteries of God.
As I pointed out before, this trade-off is fully under control of a saint. As a result, he can switch between the two happy places at will.