Thanks for keeping everyone updated on the results you're getting, guys.
To recap:
My Sony players (480 and 590) don't have a problem playing back AVCHD 3D from disc (DVD or Blu-ray), even at the higher data rate. Those videos were originally rendered to SD card in Edius (as AVCHD 3D folders with the AVCHD 3D Writer export option), then burned straight to disc with ImgBurn. My Epson projector down-converts the 3D to low resolution, but my LG passive 3D TV displays it just like it does other Full HD 3D. The Panasonic 320 player won't play AVCHD 3D folders burned to DVD. Other equipment combinations will likely yield similarly inconsistent results with AVCHD 3D.
IMO, Edius is the editor of choice for JVC users. It's stable and 3D playback is smoother than anything else I've used (at any price). Playback is much better than Vegas Pro 12 or PowerDirector. This is a huge factor when editing 3D. I'm using a Core i7 3930 OCed, with a middle of the road nVidia card (2GB GeForce 560, about $200). The drawback with Edius, of course, is that it won't let you burn a 3D disc directly, so you still have to go through other software to do that. The exception to that rule now is Grass Valley's addition of AVCHD 3D Writer option for SD output. Although it's basically without menus, it lets you use Edius/ImgBurn to burn to SD card, then put that on a disc. With the right combination of hardware, this allows you to get high quality Full HD 3D results with 60i material. Render times, however, are very, very long.
I still think converting to 1280x720/60p is the best choice for many projects. I use it for family events when very high resolution isn't necessary but smooth motion is. And it plays on any 3D player. PowerDirector will let you do this for JVC mp4 files, but not AVCHD 3D. Hopefully, Cyberlink will add support for JVC AVCHD 3D files, too, but it's far from guaranteed.
The only software that allow you to create higher quality output (original, in fact) is MediaBrowser, the free software that JVC provides to purchasers of the TD1/HMZ1. Footage is maintained in the original quality, but you have virtually no editing tools to work with. Still, for very simple editing and playback, this option is fastest and maintains the best quality. For everything but fades and title overlays, the footage is identical to the original.