licensed (proofed) technology is often not as vulnerable to bugs as selfmade technology. Result: lesser bugs or at least lesser trouble fixing bugs.
And if theire are bugs you don't have to be angry with yourself. Remember the Gamebryo team is just 1 phone call away <img src="/ubbthreads/images/graemlins/devil.gif" alt="" /> <img src="/ubbthreads/images/graemlins/evilgrin1.gif" alt="" />