tbh i would have gone for the q7 but my wife doesnt like them, just a style/ taste decision. apparently the drive in the GL is a bit better, the q7s are maybe a little cheaper, slightly larger 4.2lt engine but we wont use it off road much. i used to have an 18ft boat but not at moment, a small trailered boat is probably the most we will use the off road and towing capability for. we couldn't fit 3 child seats in the 3 series and if we have visitors the extra two seats will be useful.