First off, let me state, as the owner of both the XVT3D650SV (purchased from Sam's last Feb.) and the LG 65LW6500 (purchased last Tues.), I LOVE BOTH TV's!
I have also completely read through both this thread and the LW6500 series thread in their entirety.
I will give my opinion for what it's worth for any one interested in one or the other.
My Vizio has deeper blacks and looks great out of the box, Picture in Picture, but has VERY few settings, much more simplistic menus compared to the LG, and a problem with leaving a discolored almost purplish "smear" when people move on shows (didn't notice it after a few months though).
My LG, local dimming doesn't compare at all to my Vizio, doesn't have PIP, but has awesome features that Vizio doesn't such as 2D-3D conversion, HD upscaling, and service menu unlockable features such as THX MODES, DVR function, local dimming menu enable.
3D is better on the LG ONLY if you are seated precisely at eye level with TV. and has settings independently of 2D.
One last important note. I received a full reimbursement for my purchase of the Vizio when I noticed a constant dim area had developed toward bottom center of screen because these panels CAN NOT BE FIXED, only replacement TV or refund thanks to the extended warranty! YES I Now own both, but had to buy a LG ONLY so I would have a fixable TV in the future.
Hope this helps.
DO NOT PURCHASE ANY NEW TV WITHOUT AN EXTENDED WARRANTY!!!!!