FVS336Gv3 vs WNDR4500

Apologies if I'm in the wrong section, I could not find a router community.  My question is which router should I use as my WAN gateway, an FVS336Gv3 or a WNDR4500?

Here's the background...

I was looking to setup parental controls on my router (FVS336Gv3) but quickly learned the firmware does not support it.  I do however also have a supported wireless router (WNDR4500) on my home network, although I use the FVS336Gv3 for DHCP and to connect to the internet.  The WNDR4500 is just for wireless, my phone, tablet etc. (same subnet).

I did this because I figured the setup would be faster overall this way and because I felt I might need VPN also. I was also hoping to connect directly to my providers fiber (avoid their converter box) but never managed to find the adapter I needed.

If I switch these, i.e. make the WNDR4500 my primary router (and remove the other altogether) will performance be any different, i.e.worse?  Are there any other considerations I'm missing?

This is a home setup BTW. 

Any help would be greatly appreciated.

Thanks in advance!