I was hoping at least some of the more overarching issues with it would have been fixed....
Kill Code didn't really fix anything with the 5E Matrix.
If you had an issue with the way it worked, or any lack of clarity, before Kill Code was published... It almost certainly exists after Kill Code.
There were some clarifications, such as Agents can no longer run by their lonesome anymore.
The new Matrix Actions are really a double edged sword. Sure, MARK-less actions are great for PC hackers. But they just as easily hurt PC hackers because without a MARK, there is
no way to know it is being used against you / your team.
Just in case there were still groups out there running with PC team PANs, the Tag action punishes them - again without any MARKs to let the team know it is even happening.
The gear is a mixed bag. All of a sudden you can end up running up to 7 cyberprograms on commlinks now... Not to mention an additional 7 programs on cyberdecks. Maybe more, if your GM allows the two pieces of gear to stack with themselves. Program slots are nearly useless now.
I could go further into it, but won't here.
In short there is plenty of good in the book. If your table will only use the whole thing without cherry picking at all, it is even more true that PCs need to either run Wireless Off all the time, or rely on a truly benevolent GM that plays everyone else as Matrix - Ignorant.