copy vs. insert w/ no autocommit

I realize a COPY statement is much faster than individual INSERT
statements. But how does COPY compare to individual INSERTS within a
BEGIN/END or with setAutoCommit(false)? If there's a difference, are we
talking orders-of-magnitude in difference? (I am using JDBC and my
design might be affected depending on whether COPY is faster than a
prepared INSERT w/ auto-commit off.)

Matt