A trend that I've found very irritating of late among poet-critics who should know better is a tendency to be dismissive without actually having read the poetry. I don't think you can do that. It's beyond unwise: it's arrogant and wrong-headed.
Elsewhere recently, some young writer had the gall to say that he doesn't actually need to look at modernist non-representational paintings to be able to dismiss them, they're obviously about nothing. (Ignoring for the moment the truth that non-representational painting styles are indeed about nothing, in the sense that they do not and were not intended to contain content, narrative, or representation. If you expect them to, you're completely missing the point.) I can hear the outraged howling if a painter were to claim that she didn't need to actually read the writer to know he wasn't any good. That kind of dismissive criticism is facile and superficial, and puerile, no matter where it's applied, precisely because it hasn't actually engaged with the artwork it's dismissing. You cannot subsitute an air of superior of supposedly-objective judgment for actual scholarship, and get away with it. Your lack of actual research will eventually trip you up, when someone catches you in your ignorance. The honest child who isn't taken in by illusion will someday point out the emperor's nakedness.
By contrast, if I present an opinion on a poet's work, it's because I've actually taken the time to read their work. That is only right and proper, and is a requirement for honest scholarship (as opposed to opinion-mongering). And that is part of the attraction of Collected Poems anthologies: they allow you to browse in, and also do deep reading, and re-reading. They allow you develop an opinion directly from the source data, as it were, rather than from received wisdom. This is true no matter what literary-critical school or filter you are using as your baseline.
Received wisdom is almost always wrong, precisely because it overrules personal reflection and direct engagement. The issue isn't that you have chosen to believe a mistaken authority, or even a correct authority, but that you have not done your homework for yourself. Laziness in research is unforgiveable, and leads to bad opinions based on insufficient data. Questioning received wisdom (questioning authority) is precisely the method by which new discoveries are made.
So, I have on my shelf Collected Poems even by poets whose work I am neither particularly fond of nor impressed by, as well as by those poets I cherish. I read them all, and I re-read even the ones that are not my favorites, to see if I might have missed something the first or second time. Sometimes, I work my way into something redemptive, in those poems that previously have not convinced, or embodied an experience. Sometimes, on the other hand, my original opinion is confirmed. But I take the time to read them before opening my yap. That seems only fair.
There is also something satisfying, in a single-volume Collected Poems, about having as much as one can carry bound up in one volume. Efficient portability in one's reading materials cannot be underrated, whether one takes them to the academy to study, or reads them on the train, or carries them amongst one's camping gear to read on those tented nights after long hikes or drives, before sleep that is always satisfying merely because it's outdoors, under the night sky, away from the overstimulating inanities of TV, radio, and other manifestations of blaring Pop Cult. (We put the Cult in Culture!) Whenever I pack for a camping trip, or a long road trip, I toss a few books into my bag; these almost always include Basho's Narrow Road to the Interior and some Rilke.
On my shelves are Collected Poems (and Selected Poems too) of T.S. Eliot, Conrad Aiken, Rilke, Wallace Stevens, Stanley Kunitz, Sidney Lanier, May Sarton, Wlat Whitman, Emily Dickinson, Allen Ginsberg, Hart Crane, Edwin Denby, Muriel Rukeyser, William Carlos Williams, Jim Harrison, Octavio Paz, Adrienne Rich, and many others. Some favorite poets I don't have Collecteds for, for in some cases they don't exist, or I haven't purchased them yet; meanwhile, they do have excellent Selecteds: George Mackay Brown, Rumi, Neruda, and others.
The study, and the assessments, continue.