Sooooo.....
Which ones do you prefer and why?

I download Xvid... because of smaller size... and it seems that there are more seeds for Xvids.
To me, the Xvid quality is great on my LCD monitor?
What would you need the MKV higher quality for?

Also, I can not find anywhere a converter that will convert Mkv's to PlayStation Portable format.
They all say they do, but the sound comes out distorted!!!