I know Haydn from his symphonies, quartets and concertos(the former two genres he was responsible for generally founding and developing). Lo Speziale was very interesting, likewise with this 1982 production, though I do have to agree that those who are unfamiliar with the music and story would benefit from subtitles.
I cannot agree with the ungenerous and uninformed review of the first reviewer of this production. For a start, no one pretends that Haydn was a patch on Mozart as an opera composer, so the comparisons are pointless.
I was curious to hear a Haydn opera as this composer was never really known in that genre to the same extent as his younger colleague Mozart. His 1768 opera, Lo Speziale (The Apothecary) is here presented on a DVD of a 1982 performance which is certainly very stylish, well-sung and well-played.