Like this Reddit post 'submitted on 15 Sep 2011', let's assume that the reader has at least an undergraduate degree in Linguistics.
I don't know if this commenter had known of the 2006 edn of Allen and Greenough's New Latin Grammar when (s)he wrote:
Allen and Grenough is the standard traditional grammar, but like most Classics grammars, it was written well before the advent of modern linguistic theory, and thus is burdened with a fairly outdated grammatical apparatus. Most of the accidence is fine, excepting some of the historical material, but the book's syntactic description is less reliable, IMO.
I don't know why that post doesn't critique Essential Latin Grammar: Bennett's Grammar Revised (Mar 1 2007)?
That post propounds no other recommendation:
Unfortunately, there isn't one single modern grammar that can replace A&G. Latin Grammar by Dirk Panhuis is a decent attempt at applying modern linguistics to Latin grammar, but the book is not thorough enough to be a full reference grammar (plus, some of Panhuis' analyses are questionable). Panhuis seems to employ a largely Functionalist model (via Simon Dik), so he includes a large chapter on pragmatics, which is worth a look, as well. Overall, Panhuis is a good supplement to A&G.