Ok, let's have a look at this.
I disapprove of this presentation of errata, but at least it's not too expensive and come with more gear, despite the quite insulting Errata delivery, being hidden in a pdf product like this (it's bad customer service, at the very least). Also, there are several other problems with this product.
It introduces two new qualities - incompatible and vintage - that roughly do the same as the obsolescent/obsolete qualities of This Old Drone. So far so good. It also introduces a new weapons category, some new add-ons, and new rules issues. And it sneaks in an errata for an old issue.
The art ... is about 60% photomanipulations, it seems - sources apparently are their own softair guns. The other 40% are hand drawn, and those look decidedly space age. Style of Photomanip and lineart don't mesh well with each other - here photorealism dimmed slightly by PSP filters, there strong, comic-esque inking and almost no shading. Not a pretty mixture, though both styles work for themselves reasonably well. Also, the resolution of the images seems bugged, both in Foxit and in Adobe reader. Low resolution, especially in the background, scaled up, it seems. That's one large step down from Unfriendly Skies' artwork's quality, which only had one glaringly obvious photomanip (something I personally disapprove of, but ymmv).
The guns ... the numbers seem mostly okay on a first glance, but missing add-ons their fluff explicitly refers to and bizarre discrepancies between caliber and classification of weapons occur, though. Lessons learned form That Old Drone? It seems not. A substantial step back from Unfriendly Skies here, too. Also, the stats for the vintage predators don't mesh with the old stats at all. Ammo capacity seems to change with age in weapons. Who'd have thought that.
Fluff ... goes towards the bizarre. There are free-selling guns in Europe and Japan now? Excuse me? Japan? The setting where half the point is the extreme firearms ban and a return to everyone wearing a tanto to fight off frequent ninjapunk attacks? It's not like "Licenses for every piece of gear" isn't a core mechanic of SR4 SINs either, but then again, the rules have meshed badly with old rules lately anyway.
Same tone as in War!, and it annoys me in the same ways, even though not on the same magnitude. Summed up, this PDF has a general tone to it that I just find unpleasant, bizarre fluff, and sloppy rules.
Bottom line: Meh. Mixed feelings. It's substantially worse than recent releases like Unfriendly Skies or Spy Games. However, it's not quite as bad as War!, because apparently the munchkinism has been reined in to levels I am familiar with from the old FanPro German supplements (the H&K X is like the Ares Y, only with [raised stat] and costing d6*100 nuyen less), so it's not a total disaster like War. It delivers some good weapons and some that ... are various levels of nonsense and uselessnes. This still gets only 2/5 from me, because of the many factual errors, wonky stats, in parts bizarre artwork (are the chinese assault rifles attempts atabstract art?), the integrated hidden errata, rules issues, and the overall tone in the writing, as well as getting the shadowtalk voices all wrong.
[2 of 5 Stars!]