High Quality Gundam Seed Destiny Subs/RAWS

After I downloaded this version, I was amazed at the quality of the video. There wasn't any pixelation or blurred/dulled images normally found in many different fansubbed relases and the detail was amazing.

My two question are:

1. Where are other high quality RAWS of Gundam Seed Destiny such as the one linked below located?

&

2. What reasons do fansubbers have to use lower video quality on their releases instead of higher quality video? (Barring the obvious size difference)

Phase 50 (RAW Version High Quality) (500MB)