Similar to the Linksys E2000, the E3000 model adds a USB port, simultaneous dual band wifi and additional RAM. The E3000 replaces the WRT-160N.
Some reviews have complained about the low speed of the USB port. (approx 5-6Mbps)
The Linksys E3000 has a wide array of aftermarket firmware available from DD-WRT and custom versions of TomatoUSB.
Toastman build, one of the custom advanced versions of TomatoUSB: