600Mbps plan - Wifi router recommendation

I just upgraded to 600/15 MBps.

Can any one here recommend me a wifi router that will allow me to get close to that 600mbps speed through wireless?

I live in a 3000sqft 2 story home. My previous internet speed was an old 105/12 plan, and my current wifi router is a netgear Nighthawk R6700

With the R6700 I am only able to get around 250mbps out of 600mbps through wifi..

Thank you