RUN: 17 issues plus two Giant-Size 1975-80
KEY CREATORS: Roy Thomas, Steve Engelhart, etc (writers), Jim Shooter,
etc (artists)
OUTLINE: The earliest issues involved an alliance/clash between Doctor Doom and Sub-Mariner, who despite the title was not really a villain by this point. Later issues had more of a rotating cast, though it was almost
always more of a fight than team-up
STANDOUT ISSUE: #17 Red Skull, though willing to betray the Hate-Monger (Hitler version) to achieve his goals, has reservations about doing so because he shared Hitler's dream.  Hitler is the one person I can see the Red Skull have regrets about betraying, and this story is well played out.
DUD ISSUE: No single issue stands out
OVERALL: The Sub-Mariner/Doom issues are a lot duller than you'd expect from a title where Doom was a co-star.  Not much to discuss except they fight a lot, and at one point the fight spills over into (IIRC) Fantastic
Four's.  So you get a dull fight which isn't even self-contained.  I read a bunch of issues at once and the series definitely does not reward people who read multiple issues together.  The final story arc however (#16-17) with Hate-Monger and Red Skull is actually an interesting use of both villains and does not require reading the earlier issues to understand.
RECOMMENDED OR NOT? As a series, no, but do pick up the final issues
CONTINUITY NOTES: Oddly, during the Waid run of Captain America, it looked like the Cosmic Cube the Hate-Monger got trapped in in the final issue was real (admittedly of Waid's first run on Cap, I only read the
double sized issue and one other so I might not have all the facts), though it's crucial to the plot of #17 that the Cube's a fake.