Well besides not doing anything that's long, difficult, costly, not popular enough, too many words, they are definitely the best.
I really don't understand your post.
>Not long
Guin Saga, Gundam: The Origin, Knights of Sidonia, Chi's Sweet Home. I suppose they don't translate any battle manga that goes forever, but I personally don't want that anyway.
>Not difficult
Stuff by Nihei usually uses some pretty strange language. I think they challenge themselves more than any other manga publication since they also translate novels. Have you read
Sayonara, Gangsters? Surely not an easy translation.
>Not popular
I mean... I think that quite the opposite is their schtick, they translate the things that aren't popular enough: Wolfsmund, Knights of Sidonia, Utsubora, Tezuka stuff (not that popular in North America), lots of pretty unknown (unless you're into Japanese culture) Japanese novels, Lychee Light Club, Helter Skelter, etc.
>Not too many words
This is just an odd one to mention, really. Have you read everything they've done?
>Not costly
Have you seen the quality in their publication for Mobile Suit Gundam: The Origin?! It's the nicest comic I've ever seen. I'm not using hyperbole. In fact, they seem to have the nicest publications in North America. They actually use proper grammar in their translations, they paper is nice, and everything is of high quality.