Routers in home performance, do they really differ?

hey boys,
So there's a lot of routers to choose from. Different features like firewalls, interface, etc. But lets talk about general latency/ping for gaming with a real-world ISP. I imagine an expensive router may make a difference if you've got 6 computers hooked up to a 10Mb/sec ISP...

But what if you're an average joe like myself with a standard 6mb/sec cable Earthlink connection with 2 computers on it, who only uses Ethernet cables (no wireless). Will an expensive router thats supposed to have quicker download/upload rates ACTUALLY make a difference for me (as opposed to the $30 D-Link Walmart special I have)? Would a better router actually lower ping/latency #s? Thanks