I had this same question. I was torn between the Sharp's bigger screen and the passive 3D from the LG.
I went with Sharp for the bigger screen. The LG was nowhere to be found by local retailers. One called their LG rep who said they would have to special order it pre-paid. Their was only one Sharp left so I grabbed that one.
They're both available online, however, I've never had the guts to make such a large purchase online.