Without having multiple subs to make localization a non-issue, I'm not sure why one would want to crossover at the higher frequencies of 120Hz or 150Hz. The majority of 2-channel users seem to crossover around 60Hz - 80Hz.
But if half, or even a third, of my listening was at lower volume levels (and the closer you are to your speakers, the lower the levels are going to be), I think I would personally opt for the greater detail and dynamics of the GR driver.
Steve