Sam Ruby: Each format has its strengths
Sam Ruby posted a long and interesting writeup on the differences between RSS and Atom, and what tool builders need to worry about.
“[I]f you want to support any version of RSS completely, you essentially need to support all of them.”
“If you can’t generate unique ids for entries, then perhaps Atom is not the format for you.”
“Atom has more required elements than RSS. Atom adds type attributes to titles and links to resolve the ambiguity described above. It has separate elements for summary and content.”