The Form of Baptism

In his Treatise on Baptism, John Wesley writes:

Baptism is performed by “washing,” “dipping,” or “sprinkling” the person….[It] is not determined in Scripture in which of these ways it shall be done, neither by any express precept nor by any such example as clearly proves it; nor by the force of meaning of the word “baptize.”

Following Wesley, Methodists have generally been quite open in terms of the form, or mode, of how baptism is administered.  What, if any, difference do you find between sprinkling with water versus full immersion into water?