If you can find an early 07 for relatively the same price, buy that instead of the 06.
Early 07 (thru a certain VIN #) still came with the Forged Alcoas. Late 07 (after a certain VIN #) came with the knockoffs. The 07 also has the 100,000 mile powertrain warranty while the 06 does not.
If you have no intentions of modding the car, the GXP is the way to go. I had/have no intentions of modding a car, so the GXP is the perfect choice for me to drive to work and pick up my kids from school (when compared to a GT or GTP).