I did some back to back testing.
I ran speedtest.net and xtremelabs on a stock Infuse, Stock Inspire, and a Rooted Inspire.
Stock Infuse Speedtest.net .01-.02 Mbps down, .05-.01 up.
Stock Infuse xtremelabs 4.51Mbps down, .4-.5 up.
Stock Inspire Speedtest.net .02 Mbps down, .06 up.
Stock Inspire Xtreme 1.14 Mbps down, .148 up.
Rooted Inspire Speedtest.net .02 Mbps down, .51 up.
Rooted Inspire Xtremelabs 2.74 Mbps down, 2.8 up.