I had avoided these movies because I heard they were not very good - but last week I decided to give them a try after watching Keri Ford's video which mentions them.*
My overall impression is that the Star Wars prequels are worth watching, as an honest and good hearted endeavor. In terms of quality, they start badly, and get better - until Revenge of the Sith is a very good movie - with some outstanding world-building and action sequences.
But it is hard to exaggerate how embarrassingly inept The Phantom Menace can be! - considering it is a big budget movie by an experienced director. At times it looks and sounds like a cheap, daytime soap opera; and its plot is clunky and misconceived. At a basic level - in terms of script, directing and editing - it fails to communicate the story clearly. TPM takes considerable determination to wade-through...
What you do get from these prequel movies is, as I said, seriousness of intent and some nobility of vision. This is worth a lot; and stands in contrast to the recent Disney efforts which (aside from Rogue One - which was very good) are aiming to be no-more-than entertaining froth at best; but at worst are often calculatedly subversive of the depiction of Goodness that is an underlying motivation for these movies.
(I did not really appreciate this aspect in my previous Star Wars reviews. My opinion has been changed by re-watching all of the six early movies (1977-2005) in the past month. In early reviews, I considered the Disney additions simply as stand-alone movies - here, in contrast, as putative contributions to Lucas's Star Wars subcreation, his world building; which I now understand and appreciate better than before.)
The prequel is honest, heroic, takes risks, makes mistakes, demonstrates limited competence in the craft of movie-making - but (more importantly) is on the side of Goodness; in stark contrast with being rooted-in an attitude of cynical, or sniggering, subversion of the original Trilogy.
In the end, the Revenge of the Sith comes through with some moving moments; and a significant understanding of the nature of evil and the corruption of a good-but-flawed man; contrasted, as it must be, with depictions of Goodness maintained in the face of similar temptations, and despite errors of judgment.
* Keri comments at my Inklings blog; and intermittently produces
rambling, strongly New Zealandish, strangely-compelling videos on all kinds of subjects including
Owen Barfield - which is how I discovered him.