Bridge Mode? Nighthawk x6 behind Modem or Gateway??

I am currently using a 2Wire 2701hg-b gateway to connect to my AT&T ADSL.

My plan is to put a Netgear Nighthawk R8000 behind the current "Gateway".

Because bridging the 2701 is essentially turning it into just a Modem - should I get a better Modem instead.
The 2Wire 2701 is almost 8 years old. (Surprisingly, I have never had a problem wired or wireless)

Thanks