Back when I was in High School, in the early 1970s, I loved Keith Laumer's Bolo stories about gigantic cybertanks. I later designed a war game featuring early model Bolos (MK I-III) and I did illustrations for Steve Jackson's Ogre war games, which were basically Bolos with the serial numbers filed off.
What I learned creating the war game is that gigantic supertanks are very hard to make work at all. If anti-tank missiles become much more effective than APDS, and a supertank can carry an effective point defense system against anti-tank missiles, then maybe a supertank works. But neither has happened in our timeline. In the Laumerverse MK II Bolos were already a thing by 2015. But clearly, not in our universe.
So Laumer's Cold War Bolo era stories involved a lot of handwaving away of engineering issues. Even with exactly the right technological advances, roads, bridges and airlift remain as major roadblocks. And that doesn't begin to deal with tactical nukes being consumed like popcorn. The idea of firing a nuke beneath the Bolo and leaving it inverted at the bottom of an enormous crater was never addressed to my satisfaction.
In the wargame, it turned out that the Bolos worked best as only one part of a combined arms team, and needed to be used with great caution. Optimal tactics involved shoot and scoot plinking at long range far behind the front while the mobile infantry went in advance identifying targets, with artillery support from even further back, not gleefully surging forward to grind the enemy beneath your treads.
So the near future Bolo stories have not aged well. The interstellar Bolo stories, in addition, required a level of handwavium technology that made interstellar wars of conquest fought on the planet surface economically rational and common.
Because you need some seriously improbable magical technology to make that work, if you think about it.
Imagine the energy required to boost the Normandy Invasion to, say, .9 c and brake at the destination. Now imagine what it would take to send it on a FTL mission.
Compare that with what it would take to send a swarm of .9 c kill vehicles sufficient to sterilize one side of a planet without braking, and another half a planetary rotation later.
Orders of magnitude less, yes?
So the interstellar Bolo stories have not aged well for me, either. Too much suspension of disbelief required.
On this year's Hugo ballot there's a novella by Tom Kratman: Big Boys Don't Cry, that is essentially a Bolo pastiche with the serial numbers filed off. There was an earlier version that was much more explicitly derivative, with Bolos and Hellbores and Infinite Repeaters. These references have been removed in the current version, but it's still derivative, and I am still currently bouncing off the original Laumerverse, so no Hugo vote from me.
To his credit, Kratman has a few interesting things to say about the ethics of treating self-aware AI as slaves, but his meatsacks are remarkably morally obtuse about the self-aware war machines they employ. Which was a problem with Laumer as well.
However, Kratman does make his meatsack villains so thoroughly stupid, corrupt and evil that they come across as cardboard black hats, leaving the feeling that Kratman has stacked his narrative deck.
Also, if I'm reading the story correctly, the black hats have a gigantic war machine with brain damage, which they decide to provide with enough power to break a weld, power a gauss rifle and lift its 14,000 ton hull into firing position in the course of doing system diagnostics, and they also neglect to unload all of its ammunition before dragging it away to be scrapped.
Which puts them in the Hogan's Heroes zone of villains who are simultaneously very evil and very incompetent.
Also, I don't know which is sillier: the idea of giving a gigantic cybertank orgasms while it role-plays an SS tank commander as a training exercise, or gigantic cybertanks feeling uncomfortable around one of their number because it won't assume a clear male or female gender role.
Update: A previous version described the novella as Bolo fanfic rather than pastiche.