Slavov sounds good. His instrument seems suited to the music he's singing. Bonfanti's doesn't. The acoustics don't help, so I searched YouTube to hear what the voice sounds like close up:
Not bad, but it doesn't sound to me like a voice that should be singing leading Verdi roles. Apparently he was already singing Rigoletto and Don Carlo in Ernani
ten years ago. This Rossini was posted only a year ago, so it presumably represents his present work pretty well:
I guess I'd be happy enough to hear that in a college production, assuming the acting was good, but... It's just not much of an instrument, and sound technique can't make it more than it is by nature. The tone has little depth or ring; it's the sort of colorless voice we get used to hearing in Gilbert and Sullivan operettas. If the question was who stands out among present day baritones (or, originally, who's the best in the world today), I sure hope it isn't this guy.