The LCD is one of the differences, and the only other I can see is that the DIR-655 only has a 2.4ghz wireless band. The DGL-4500 has 2.4 and 5.0 ghz so in situations where there is interference on the 2.4ghz band (microwaves, telephones, etc.) you could switch to 5.0ghz. To be honest, the LCD...