Here's a short test of Twixtor's attempt at 3D slow motion. The speed was set at 12.5% (best to use even divisions of 100% for smoothest results, ie: 75% or 50% or 25% or 12.5% as this creates the simplest math and least "cogging"
Twixtor 3D slow motion sample
The playback from Youtube is full of glitches and errors - maybe time to try a different source file - this one was 1080 mp4 AVCHD
Here's the mp4 file to download - much better quality mp4 Twixtor slow motion test