Oh, and here's what you lose with YV12/YUV420/whatever:
Raw sizes @ 30 FPS (these are huge I tell you):
RGB: 5626 Kb/s
YV12: 2813 Kb/s
Lagarith RGB (static image FYI): 1034 Kb/s
Lag YV12: 772 Kb/s
Comparing "quality" of different programs of such type is silly, unless they're lossy.
With lossless ones, it's usually the colorspace conversions that degrade quality.
And as you can see with this extreme example (low resolution, vivid colors)
It's about non-existent, and your HDD will thank you for the extra space savings.
But yeah, Lagarith has for some reason been pretty slow for me as of late. .-.
Back in the day it encoded 800x600 at around 54 FPS, and was limited by I/O.
Now it encodes 640x480 @ 74 FPS, and is limited by CPU.
Guess silly Crysis 2 and noise filters+dithering.