Your router should be able to accept and transmit data pretty much as fast as
you can throw data at it, up to its maximum rated speed. I think it's highly
unlikely that your router is responsible for what you're experiencing, unless
it's dying on you, in which case I would expect it to just die rather than slow
traffic down.

It may be that you're just trying to access a very, very popular site and the
bandwidth problems are actually at the server end.

Verizon, however, are known to have traffic shaping measures in place,
particularly to limit p2p, but they may have extended it to other services or
high usage customers. I would strongly suspect that this is the culprit and
would strongly recommend switching to a better ISP.