{He'} (v) = smell, emit odor

Does this mean "to smell/emit odor" in a nice way, or in a bad way ?

No, the bad version is He'So'. There is no good version. He' is neutral.

KGT:

The verb meaning "smell"—that is, "sense odors"—is largh. The word for "emit a smell" is He'. This does not necessarily imply a bad smell. Odors are not considered "good" or "bad"; they are just odors. There may be a subjective evaluation of the <source> of the odor, however. It is a compliment to suggest that someone smells like rokeg blood pie not because the smell itself is good, but rather because the food carries with it positive associations. On the other hand, it is most insulting to say that someone smells like rotting forshak.

-- 
SuStel
http://trimboli.name