Assuming the hype is true and SpeedBooster actually performs as marketed, it's only worth switching to the SpeedBooster model if:
<1> all your other devices are also equiped with SpeedBooster adapters
<2> you're using wireless to transmit large data sets across an internal network
And definitely NOT worth it if
<3> you're using your wireless router only for distributing internet access; SpeedBooster won't help b/c most broadband connections are far slower than the standard wireless-G speeds, anyway