I can share a recent experience: when demo-ing a Sony active 3d tv (one of the latest and expensive models), the movements were "jerky" (like it was happening at a lower fps). But with the glasses off the movements were smoother (although with the double image). The video being played was an official Sony demo clip. I don't know if it was the 3D shutter which was causing the problem or something else, but I concluded I don't want to go the Active 3D route.
Moreover I don't like Active 3D glasses, even the lighter ones are heavy and not comfortable for extended viewing. And if you have kids who may want to watch 3D content - forget it, they're way too big, bulky, heavy and uncomfortable for them.
These days you can buy 5 to 20 passive glasses for the price of one active set. One consideration if you want more glasses at home.
I was not too concerned about the resolution as I plan to sit about 12' away from my screen.
Sorry to not answer specifically about LG or Samsung, but these technologies are so vastly different, that you should first decide on this matter - that is if 3D is an important requirement.