Byrne's last volume certainly continues to show off the post-Crisis flavor of Superman, but other than the Supergirl saga that ends it, it's largely forgettable due to its focus on single-issue stories (and the move away from new Luthor, one of the most interesting elements of post-Crisis. But we do end with that Supergirl saga, which would determine the focus of Superman for the next year.
Checkmate (Action 598). Pretty much a teaser for Checkmate, but it's a good teaser that makes me want to revisit the series in trade paperbacks! A nice post-crisis introduction [4+/5].
Prankster (Superman 16). The reinvention of the Prankster as a failed TV comedian gives him some new depth, but otherwise his schtick of jokes and pranks remains very Silver Age [3+/5].
Superbot (AoS 439+440). This starts off with a great little story with a Silver Age vibe, as a Super'bot mysteriously appears thinking its Superman. Add in a lot of supporting cast members, and you get a superior story. The follow-up issue is then all subplot, revealing not just the origins of the 'bot but also filling out a lot of other ongoing story. AoS was often the best comic of this era, and these issues demonstrate why. [5/5].
Metal Men (Action 599). Maybe the first take on a Kryptonian Metal Man? Certainly doesn't seem fresh now. And Byrne's take on Luthor in this issue is remarkably stale too. This isn't the clever business man, but instead a gloating megalomaniac who should have been thrown into jail afterward [2+/5].
Silver Banshee Returns (Superman 17). I applaud Byrne for introducing new villains to the Superman mythology, and this Irish-focused villain is perhaps no weirder than the Bronze Age demons that Superman faced, but handing off the finale of the fight to someone we've never seen before drags the comic down, even if it extends Silver Banshee's mythology [3/5].
Wonder Woman (Action 600). The finale to Superman in Action (for now) brings us an attempted romance between Diana and Clark and an attempted assault upon Olympus by Darkseid. They were both interesting twists that wouldn't have been considered pre-Crisis, and so were probably very exciting at the time, even if they seem more staid now. As for the rest of the stories: seeing Lois' reaction to the "romance" is terrific, then we get an interesting view of future problems for Lex, and the rest is a prelude to the next Superman issue ... [4/5].
Return to Krypton (Superman 18). This story has a great science-fiction beginning, with the radiation from Krypton's destruction arriving on Earth, and then Superman getting his first view of the dead planet. But from there it descends into a hallucination, and then the Kryptonite problems seems offhandedly dealt with. A definite misfire [2+/5].
Mxy (AoS 441). Byrne made some good changes to Mxy, such as putting him on a 90-day timer and mixing up how he gets sent home, the latter of which shows up for the first time here. But this Mxy issue is still a dull fight, even it's interrupted by any number of subplots [3/5].
Power Play (Superman 19 + AoS 442). Some aliens (kinda) come to Earth and suck away Superman's powers (kinda) until they're overpowered and defeated (somehow). A somewhat dull main story in large part because the antagonists are entirely two-dimensional. Perhaps all the heroes showing up to help was more interesting in these early post-Crisis years? Fortunately, there are subplots about Luthor and the new Supergirl that keep things slightly interesting [3/5].
Doom Patrol (DP + Superman 20). Another crossover showing off the state of the early post-Crisis universe, this time with the New Doom Patrol, a short time before Grant Morrison took over. This crossover has a lot of neat elements, such as the return of Metallo as part of Byrne's ongoing continuity for the Superman titles and the increasing mystery of the new Supergirl. Beyond that: it's a decently interesting fight [3+/5].
Hostage Crisis (AoS 443). A weird story by Ordway. Probably it tries to lean on pulp themes, but this combination of the Middle-east, terrorism, and aliens from another dimension is just plain weird ... and runs a little long [3/5].
The Supergirl Saga (SM 21-22 + AoS 444). Byrne's Superman too often focused on one-off stories that didn't take good advantage of the serialized form. It's great that he ended his run on one of the most carefully serialized arcs: not only a three-parter, but one that builds on the famous Death-of-Superboy arc in the Legion of Superheroes. It's a nice expansion that tells us the story of what happens to a world when the heroes abandon it, and it of course sets us on the road to Exile [4+/5].
The Cadmus Project (SM A #2). The post-Crisis return of the Cadmus Project is well done, with its generational use of the Newsboy Legion and their adult counterparts. There's so much great material here, both reiteration Kirby's work of the 70s and expanding it into the new Superboy and more [4/5].
Private Lives: Love's Labor (SM A #2). A great little story about Maggie & Turpin. If we'd only had more of this! [5/5].