Also, "repetitive" isn't automatically a criticism but objectively, "Sextant" is absolutely a repetitive album in the same way "On The Corner" is- the majority of both albums is groove based and the first 2 cuts on "Sextant" in particular are built upon what could be goofy little keyboard samples. I can get into repetitive music but only if it's done right, which is pretty difficult to pull off. Miles is arguably one of the best when it comes to this so saying that Herbie doesn't quite measure up isn't really that much of a slam against the artist or album, more of an observation.
And ugliness can be great as well (need I remind you of my all time favorite album?) but when *combine* with repetition, well that's *especially* hard to pull off (I definitely wouldn't call "B*itches Brew" repetitive). "Sister Ray" is perhaps the ultimate example of an ugly, repetitive epic that somehow works ridiculously well.