Thoughts on the Jason Aaron part
It's pretty brief, so there's not a lot to glean here.
As I said above, Burnham's art was good. I guess there's no need to comment more on how much I enjoyed the art because I'm not sure if he'll ever be returning to TMNT. But I will say that the art somehow fit the vibe and setting of this story perfectly.
The whole idea of the Sunshine Safari Park was pretty believable. I could totally envision a scuffed facility in the deep south where mutants are held. It kind of reminds me of a mix between those big cat facilities as seen on Tiger King and underground animal fighting. It also reminded me of how Mikey was detained in the Lost Years comic. It's an interesting idea to explore. I like this setting and I'm excited for the Donatello issue so we can see more of it.
When Donnie was fighting the guards, my first thought was that "oh come on, he could easily beat the fuck out of these two guys" but I think the story did a good job of showing that he was extremely hungry, delirious, and not at full energy. Also, his intention wasn't to escape at all! He was just trying to get a sandwich for the other captured mutants. I'm not 100% sure if I can buy this sort of altruism though (and I'm not really sure if a ninja turtle should really care this much about strangers). If Donnie was really so hungry and delirious to the point where he can't remember his name and he thinks a common rat is Master Splinter, would he really execute such a sophisticated plan just to grab a sandwich that he wouldn't even be the one eating? At that point, you'd think it would be every man (or turtle) for himself.
But one bright spot in this story: it didn't feel like there was a racial/bigotry allegory to the whole thing despite the facility being located in the deep south, so that was nice and refreshing. Obviously, the guys who run the facility don't look at the mutants as people, and ignorantly only see them as animals, but it didn't beat you over the head with over-the-top moralism. In other words, it seemed like Jason Aaron was more interested in telling an actual story than just preaching the same shallow message that we've heard a million times before.
Thoughts on the Tom Waltz part
I really see this part as a necessary prelude to the upcoming Mutant Nation side-series or any other side-stories they're cooking up. It's nice to get an update to see where all of these characters are at, and it was nice to finally see the motherfucking Mutagen Man return after mysteriously disappearing for so long.
But really, I'm not that interested in these characters, and plots with these characters were often the low point of the main comic for me. So even if I thought Waltz did a good job with the story, it's not something I would have ever been excited about to begin with.
However, I think putting Gavin Smith on this story was a great idea, because the story feels like such a natural continuation of the work he did on the previous ongoing comic — it has many of the same characters and themes that were in the issues he did the art for previously.
Also, I think it's good and healthy for the overall IDW TMNT universe that Old Hob is continuing to create a sort of mutant separatist colony. It's a nice foil to the cringe Sally Pride and Mutant Town component to the story. I really despise the idea of mutants living out in the open alongside humans for multiple reasons I won't go into detail about here, but the presence of Hob's separatist group at least gives me a faction to root for.
Speaking of rooting for people, I'm crossing my fingers and hoping that the spider-mutant version of Lindsey ends up consuming all of the mutants and putting an end to Mutant Town for good. If that doesn't happen, then I'll at least settle for this leading to a storyline where a de-mutagen needs to be developed to de-mutate her (because she's too dangerous), which would then be administered to all of the previously-human mutants. Either way, I can see how this story might be a pathway toward demutation. Let's hope that happens.