Longinus' On the Sublime is so unique from any text we have read so far because we don't have any personal information about Longinus, and it was written in letter format to a friend, as opposed to a classic theorist or rhetorician writing specifically for the masses to understand their theory. Longinus probably didn't think anybody except for "Postumius Terentianus" was going to read his work during that time period, let alone think it would be republished as late as 1554 and still be studied today. I wonder if Longinus would have written his thoughts differently if he had known that his work would be studied for centuries.
I have read both Homer's the Iliad and the Odyssey haven't never read about any criticism towards either works. I have always heard about them being praised for being so great until Longinus criticized the Odyssey for having too much storytelling, which Longinus says is natural since Homer was older then.
The one thing that I couldn't quite wrap my head around was the relationship between emotion and sublimity. When Longinus talks about Caecilius omitted emotion from his list of productive sources of sublimity, I think he was trying to say that sublimity and emotion do not necessarily go together, but emotion in the right place can make something sublime.