I think the problem is that none of them do a particularly good job and all have some gotchas.
I own a 2010 Samsung 63" 3D plasma (PN63000) on which the 2D>3D ranges from average to poor as the algorithms used simply do not properly interpret and depth cues.
I also have a 55" LG LM7600 which does a pretty good job but still gets tripped up with certain colors, generally pushing blacks into the background and reds outward.
Of the two, I get some mileage from the LG but neither of them would be mistaken for native 3D and neither can do any 3D pop out of the screen.
Based on my experience, on the fly 3D conversion has a long long way to go before being really viable.
Xbox Live: XboxPhantom