Well I did try out the 42" variant at the LG store & the pq is not even close to the active shutter glass counterparts. The images r not sharp & there was some cross talk too (even though LG claims that there's 0 cross talk).
Right now, LG is the only brand who has rolled out Pssive TVs, but this year Samsung is gonna roll out their passive glass tv, in colabaration with Real D. So I suggest to hold off you purchase, until then coz LG ones r simply not worth it.