Rainey is intelligent, clear, and engaging. He clearly defines the terms relevant to the anthology (or at least tackles the problem of defining "modernism" succinctly). And it's helpful to have an anthology which is (more or less) in chronological order. All in all, Rainey makes a valiant effort to clarify any detail in the confusing texts/authors' lives that needs clarifying. He addresses the reader frankly and with a sense of humor, which is refreshing after slogging through dry critical writings found in other academic anthologies (like the Companion to Yeats which I just finished...).
As with any anthology, though, it has its limitations:
Not *every* confusing detail is clarified.
I'm not sure I agree with Rainey's leaving out certain non-while-male modernist writers to avoid "tokenism."
Its personable tone can make it feel a little less-than-academic (like when Rainey refers in passing to the enjoyability of T.S. Eliot's children's poetry, like it's objectively rather than subjectively true).