So it looks like a bug with stroke rendering on text in Media Encoder:
- After Effects 2015.0.1, Build 22.214.171.124
- Media Encoder 2015.0.1, Build 126.96.36.199
The red text in the examples above has a white stroke (i.e. outline) applied to it with the stroke set to "Fill over Stroke". Removing the stroke and re-rendering in Media Encoder appears to render the text smoothly, albeit without the stroke I actually wanted on it.
I would first try to change the color a bit. MPEG compression hates solid saturated colors next to white or black.
Rick, thanks for the feedback, but it's not MPEG compression. The workaround I provided above fixes the issue.
It's probably a rendering bug on stroke.