Well, I'm sending the VT20 back today, and it is really, really hard to say goodbye to this wonderful TV. I'll just sum up all the things I wanted to say about the plasma:
Generally it's a great TV, both in 2D and in 3D. The THX mode almost doesn't require calibration. In 3D however, it's important to adjust the brightness because of the glasses, but it's not something you wouldn't know already.
3D is a HDMI-only thing (you can watch 3D television via the standard connector though) which means you either plug your computer or console to the TV, or you really should consider buying the 3D Blu-ray player. You should buy it anyway, because the 3D movies look just great in the 3D Blu-ray format.
The glasses...well, I have mixed feelings about them. They work ok, but I think the Samsung ones are more roubust and practical. They also look weird.
The TV has 2 USB ports, but you can't watch 3D movies from your pendrive, unless you plug it to the Blu-ray player, the same goes to D-Sub an any other port.
You can forget about streaming 3D directly from Youtube while using the wireless usb dongle, because of the ugly quality of Youtube movies. When using the TV internet connection the movies look much worse than the regular 360p Youtube quality.
We didn't test the external HDD recording option, because it requires formating the disc. You can then play the content back ONLY on the TV that recorded it. Maybe, just maybe there's an option to record 3D too, and then play it back while the HDD is connected to the player.
Cloudy with a chance of meatballs looks great in 3D on that TV, but I think you could throw a lot more 3D effects into the movie. Don't get me wrong, it's 3D through the entire movie, and there's a couple of pop up moments, but still, I could use some more cowbell, I mean 3D.
We also had the Panasonic 3D Blu-ray demo disc. Well, some of the clips were cool, some weren't, but the best of them is to my surprise the coral reef one. It didn't have a lot of depth, but it certainly had this chillout-ish atmosphere of fish floating in front of the screen. Animals generally look great in 3D. Especially macro shots of insects and other scary little creatures.
3D pictures also look amazing. I recommend downloading the .mov slideshows from cesarsommer.com and playing them on the TV - just wow.
Football looks kinda cool too. Especially when the camera is closer to the action. It's more immersive than the regular 2D version for sure.
Gaming... It's awesome! Really, if you're a gamer, 3D gaming on 3DTV is the holly grail. I tested ArmA 2 and Avatar, and both games are fantastic in 3D. I desperately wanted to test Richard Burns Rally, but I somehow couldn't properly set the iz3D driver, which is strange, because RBR is on the supported titles list.
The biggest disadvantage for me is the lack of dedicated 3D buttons on the remote. Imagine that you have a couple gigs of 3D movies downloaded on your PC, a lot of them uses different 3D settings, and in order to watch them you need to constantly change things, and experiment a lot by turning the 3D on and off. There isn't even a 3D on/off button! And you NEED to turn it off in odred to do anything on you PC. Clicking blindly on a blurry screen isn't an option, believe me.
To access the 3D menu you need to click the viera tools button, then select the 3D option, chose the proper mode ("Top and Bottom" or "Side by Side") and the 3D sequence, and then exit the menu to even see if it's working.
Glasses (it's not a real issue, they just seem to be just a bit less robust than the Samsung ones)
HDMI-only 3D, again afaik Samsung does 3D from USB
No 3D buttons on the remote
No 2D to 3D convertion, not a big issue, but with it the TV would be perfect
Polish version of the VT20 3D Plasma review http://www.3dready.pl/recenzja-plazmy-vt20/