I can't really say for sure, but I imagine that they are both roughly the same.
I think both groups just re-encode releases. So it doesn't matter much.

Hopes this helps!

"Better"
Without downloading both to test (which no one probably would), I would say the youshikibi 720p will be better visually.  The translation should be the same, as both are from the same source, Thora -which happened to be the highest rated version for this show at AniDb.

The reasons for my choice:
1. The deadfish 1080p actually has a smaller file size than the youshikibi 720p, so you either have a "thin" 1080p or a "fat" 720p, so to speak.  The original Thora 1080p is 7.1GB and 720p is 3.2GB.  Another way of thinking about this is that deadfish is around 1/7th the size of the 1080p original, but youshikibi is only about 1/2 the size of the 720p original.
2. The preview pictures for each.  I see crisp images in the youshikibi (the newspaper, for example).  I see muddled stuff in the deadfish previews.

Lacking any other info, I would say go with whichever preview pictures you prefer.  Also, if you're using re-encodes due to slower hardware, the 720p is probably a better choice.

I forgot to mention audio --the youshikibi probably sounds better on most systems (ac-3 dolby digital, 2 channel but 3X the overall bit rate of deadfish's AAC 6 channel.)