zipcpi: The case against "lo"
Note: the title is an exaggeration. I still use lo the most often out of all the gadri; this is merely an argument as to why alternatives are needed.
Here is the problem: lo has at least four meanings.
Deictic case: There are specific referents within the universe of discourse that I wish to refer to right now. E.g. "Give me the two apples." (probably on the table nearby or something.)
Non-specific case: There is a set of referents that you refer to, but the difference between the members within the set is not important. "Give me any two apples."
Generalistic case: You are generalizing about a set of referents, without making any comment as to which members they apply to. "I like apples." "Apples are delicious."
Definitional/essentialistic case: You are defining or expressing an opinion about what distinguishes a member of the set of referents, from a non-member. "Apples are a type of fruit."
Most of the time, this ambiguity is not a problem, but it often is beneficial to disambiguate. [e.g. Did you like the play? (probably the one you just watched), or Do you like plays? (in general)] Unfortunately, Lojban currently lacks a system to easily disambiguate between these cases.