What is a critical appreciation of Milton's "L'Allegro"?

"L'Allegro" ("The Happy Man") is a prime example of Milton's skill in using words for the sheer beauty of their sound as well for the ability to express a single thought with a long series of rich, poetic images.
Due to changing tastes, Milton's verse has, through the centuries, been at times overly praised, and at other times, overly criticized. In the early part of the twentieth-century, the so-called New Critics, led by T.S. Eliot and F.R. Leavis, condemned Milton's poetry as stilted, long winded, and dull, filled with artificial complexity and revealing a disconnect between Milton's thought and his means of expressing it. But even these hostile critics did not deny the musicality of Milton's verse. The pastoral poems Milton wrote in his youth—in addition to "L'Allegro," "Il Penseroso" and "Lycidas"— reveal a freshness lacking in some of his later poetry, including much of Paradise Lost. In his effortless recitation of classical and mythological names, Milton is at his strongest.
For all of its seemingly straightforward depiction of rustic happiness, there is a deliberate inconsistency within the mental atmosphere of "L'Allegro." Why, one asks, would Milton feel the need to allude to Ben Jonson and Shakespeare in a pastoral poem? Why, also, is it even necessary to begin the poem with an angry address to the "loathed Melancholy"? Basically, these are manifestations of what some today could, arguably, see as an over-the-top feature of Milton. Beautiful as the poem is, it does seem, at least to some people (not only the anti-Milton New Critics), over-extended and verbose. These are qualities, however, which Milton lovers might also see in his poetry, but to them, they would be assets rather than defects.