MAC address Filtering

I recently purchased the netgear orbi RBR50 router with one RBS50 satellite. I upgraded from an old WRN3500 netgear wireless router. With the older router, I did not use any security passwords (WPA or PSK) as I used the MAC filtering in the firmware. I had no problems with that method.  I want to do the same thing with this orbi. Since the orbi is a Tri Band router is it susceptible to someone fishing around on my network if I don't use security?