We should also look at some of the Holy Sonnets to see his clever and sophisticated use of language to convey some very important themes. I especially admire his point in "Death be not proud." Here he is using apostrophe to directly address the entity of death, and he uses a variety of other literary techniques in creative ways to "put death in its place" so to speak.
I also admire "Batter my heart three person God." Here he uses wonderful balance in his metaphors for God as Father, Son and Spirit, as well as the associations made to those three persons: "knock, breathe, [and] shine" in order to "break, blow, [and] burn" him into being a better person than he was before. Simply masterful!
One must take into consideration all of his poems as a whole. Donne has amazing control of the English language and his unusual comparisons such as the gold ring and the compass to represent his love in "Valediction" and the flea's life cycle to represent his love in "The Flea" are more than creative. They are masterful. Other poems are also evident of his wit and clever use of language to convince his reader and perhaps other persons in the poems of his purpose.
Of course, we must realize that some of his poetry is more of the "carpe diem" set than the metaphysical. Overall, however, I believe Donne to be an amazing example of the metaphysical poets.
Yes, I do. It is clear that although this label has been created and can be hotly debated, its general method of grouping together poets who use conceits--elaborate and unlikely comparisons--is something that can tangibly and usefully be used to classify poets. Donne was a master of using conceits in his work, and you only have to read poems such as "The Flea" or "A Valediction: Forbidding Mourning" to see excellent conceits in action.
I completely agree, his conceits in both poems are incredible. However I wonder, can be solely classed as a metaphysical poet? Due to the physical nature of love he describes in the elegy: To His Mistress Going To Bed.