There are quite a few people who get sick, and headaches watching 3DTV's effect. Samsung did a study a few years back, and found that 17% of people who viewed 3D programming will get sick due to the stereoscopic image tricking the brain. Our brain really doesn't like to be tricked. 3-9% of people are stereo blind, meaning they can't view any 3D at all. Another study suggests somewhere around 50% of people will get headaches after a full length movie. If you're one of the people who doesn't get sick, or headaches, i guess 3D wouldn't be that bad. I actually enjoy 3D for gaming, but have a rough time with movies. Regardless of the technology (Active or Passive, i'm sure there will be many pro LG comments following), some people just can't view 3D. I for one, don't feel 3D adds anything to the moviegoing experience, so i'll stick with good old 2D for movies, and 3D (where i can take constant breaks) for games.
I do agree that the problem of dizziness and headaches was pretty reoccurring in the previous generation of 3D TV’s. Mainly as most of the 3D TV’s at the time were active 3D’s. But since the advent of passive 3D, the problem has been curbed. This is largely down to the fact that passive 3D is pretty similar to watching 3D in a cinema theater and battery-charged glasses are not required to view 3D on these TV’s.
It's comparable to motion sickness, some people have it and some people don't.
It's also dependent on the viewing environment upto quite an extent.
But basically if getting a 3D tele is just a few hundred buck more expensive, even though you may not want to view the stuff in 3D , it's worth the money. It's like something that's better having than not having if needed.
And it is not necessary to watch everything in 3D, the teles have an option to view even a 3D program in 2D. So it's basically just like a front facing cam on the phone, which you may use just once in a blue moon but still have it.