One difference is tone. Though both speak of loss:
But age fares against him, his face paleth,
Grey-haired he groaneth, knows gone companions,
Lordly men are to earth o'ergiven,
Nor may he then the flesh-cover, whose life ceaseth,
If Winter Comes
I bumped into him yesterday was that he didn't look very cheery. Looked to me rather as though he'd lost something and was wondering where it was.
the authors create opposite sorts of tones (tone conveys the narrator's opinion or feeling about the topic addresses). Pound develops a melancholy tone, befitting loss, while Hutchinson develops a cheery tone.
May I for my own self song's truth reckon,
Journey's jargon, how I in harsh days
Hardship endured oft.
Bitter breast-cares have I abided,
Known on my keel many a care's hold,
If Winter Comes
Encountering [Sabre] hereabouts, one who had shared school days with him at his preparatory school so much as twenty-four years back would have found matter for recognition.
A usefully garrulous person, one Hapgood, a solicitor, found much.
"Whom do you think I met yesterday? Old Sabre! You remember old Sabre at old Wickamote's?...
It has not yet been mentioned that "The Seafarer" is not Ezra Pound's original work; that is, the translation is his work, but the original text is not. This gives it another layer of distance from the reader; it is often hard to fully understand a translation, since much of the textual and nuance depends on the original vernacular. If Winter Comes, in contrast, is read in English as the author intended; this is a significant difference.
The obvious difference is that one is a poem and the other is a novel. Another key difference is that one is a translation and the other is an original work. Yet another difference is that one focuses on just one character, while the number of other characters in the novel is considerably larger. The similarities of theme and plot have already been mentioned. The novel sounds intriguing, and I thank you very much for calling it to my attention.
The key theme of reflection and wondering about our lives is the principal way in which these two texts can be linked. Both feature somebody looking back on their lives and the kind of decisions that they have made and the actions that they have committed and looking upon them with new eyes, weighing up their value and thinking very carefully about how their lives could have been slightly different. This is certainly a common theme in a number of literary texts.
Thank you so much!