I read both m7 and ju-ni, because sometime I like m7 translation better than ju-ni, and other times I like ju-ni than m7. I even feel a couple of times I understand better with two translations . So, I recommend you read both, and keep what you like at the end.
About the quality, well I just want to read it, I don't care much as long as it's not too blur (which in this case, both ju-ni and m7 usually release MQ at least).
They are all good, it just depends on your preference.
I don't know about Manga Rain.