Modem/router or AirPort Express for internet?

During my quest to solve intermittent DSL dropouts it has come to my attention (if I may call what I have at 78 attention) that my Earthlink router/modem (P-660R ELNK) assigns IP addresses using DHCP. I have a wireless network that I use for downloading movies with AirPort Supreme as my base station. I understand that either can be set up in bridge mode (which is how my AES is configured to communicate with my Tivo and stereo).

My question is: Is there any advantage to changing the P-660R to bridge mode and configuring the AES to handle the DHCP routing, or is it a moot point?
Being somewhat tech and chronologically challenged, I have not been able to find anything that addresses this subject.

Thank you