Active vs Passive 3D - One should distinguish between the 3D technologies, rather than the brand names such as LG and Sony.
Perhaps you didn't realize that LG also makes an Active 60" 3D TV, and I have one. Sony also makes a passive 3D TV option. The choices between active & passive 3d is a personal choice.
They each have advantages and disadvantages. For example, passive displays reduce the overall resolution of the image. People argue that combined with multiple views (left/right) it is equivalent, but that is FAR from the case. Try reading small text or looking at fine lines with passive 3D.. you will see jagged edges that are typically reserved for lower resolutions. Worse yet, there is no anti-aliasing to smooth out the edges, as in 3D graphical environments. It's almost like looking through a screen window. The new 4K HD standard will produce fantastic new passive 3D TV's and that's what you want if you can hold out for it.
Active 3D reserves full resolution but does flicker at lower speeds. 120Hz refresh rates and above are required to produce a 60Hz image for each eye to reduce the flicker effect. The displays are getting better and faster, so this will be resolved in time. Most active 3D monitors (often coupled with Nvidia 3D vision) already eliminate visible flicker.
I hope this helps.
Best Wishes,
Chris