Overall, there's no doubt that watching the passive set was a more 'natural' and certainly less tiring experience than watching the active one. However...
We really missed on the passive set the resolution offered by the active one. This, of course, is down to the single insurmountable issue with passive 3D tech whereby it effectively halves the vertical resolution of the image that hits each eye.
Passive supporters suggest that once each eye is receiving its 3D image, you still get an HD-like impression. But watching the active and passive screens side by side with exactly the same content on each, the passive set's pictures look markedly less crisp and detailed.
The passive set also delivers a less dramatic 3D effect, with less distance between foreground and background objects.
There were a couple of other significant differences between the active and passive 21:9 TVs that seem to have more to do with the different screen technologies at their hearts than differences in the passive and active 3D effects. For the active 21:9 TV's use of direct LED lighting with local dimming lets it score significant advantages over the edge-LED passive 21:9 set when it comes to colour dynamism and, especially, black level response.
Dark scenes looked inkily black on the active set, but rather grey and washed out on the passive set. Furthermore, there were some pretty obvious issues with backlight uniformity on the passive model - a common complaint with edge LED TVs.
Overall, especially with these last two screen tech issues in mind, we'd have to say we preferred the active 21:9 TV's 3D pictures, despite their definite issues with crosstalk.
But before you consider this opinion to be gospel, we have to stress that our hands on wasn't done using a Sky 3D side by side feed (a 3D format that seems nicely suited to the passive 3D approach). Also, the Cinema 21:9 Gold samples we were using were far from final production models, and were being forced to work harder in brightness terms in a show-room environment than they would in a normal home.
The bottom line, then is that we really need to get a Cinema 21:9 Gold installed in our test rooms before any definitive conclusions can be reached. But even these early Gold samples have done enough to at least make the arrival of a finished model a day that we're seriously looking forward to.