Word of Warning: I most use RPG sourcebooks as a pleasure reading material and rarely get to actually play games. With that said...
Hc Svnt Dracones was... well first thing poorly named, but not being able to actually name the product to friends and family when talking about what you've been reading up on is more a personal problem. More importantly, it's an interesting setting whose flaws can easilly be overlooked.
This is mostly because it's lore and backstory suffer from building an interesting world and then justifying it post execution. The further back you go, the worst it gets. One can look at the various MegaCorporations rising to power and justify them without even making a "susped disbielf role", but going back to the origin and trying to justify the actions that got us from our world to Vector world are... thin. Small things like why did they stick with a corporate structure rather than transitioning to a post money economy? And not just Mars; money is a human invention, so when faced with global bankruptcy against a coproations whose main power was just that they were rich, why wouldn't the goverment toss currency aside? And let's not forget China; they shouldn't have been lumped up with the 'other nations' as far as predictable behavior.
Thankfully, small problems are small, and the further one gets away from ancient issue the writers just wanted to sweep under the rug and into the real meat of the fururistic setting, the better things are. The MegaCorps serve their roles of being in the background unless you want them in the foreground, the morphs and implants and genetic modifications are well written out, and the slight touch of eldrich horror is interesting even to someone like me who normally isn't into that sort of thing. Additional grain of salt, the descriptions on the gear is less throughly fleshed out than the stuff being put into your character's body; push frames in particular were very difficult for me to envision, and with the existance of quadreped sentient animals in need of such tools to deal with their handicap. Descriptions of the families also leaves one wanting, particularly if one reads this book alongside the expansion where we not only got descriptions of families but engrossing details on the species as well.
The dice system is curious and personally I think it has a lot of potential for definining a character. But as said before I haven't actually played any game sessions yet and possibly never will. The idea of "get as many eights as possible" does scare me a little, so does the rather popular storyteller system as well. Friends and family I've talked to about the issue say it has a similar construction to the Marvel setting, only they use larger dice becasuse... well literal superheros.
Overall, I think this setting has a lot of potential with a Guide that is willing to write their own material. If it doesn't seem that way given what I've written, just remember that one can normally say a dozen things about how something is wrong, but most of the time descriptions how of something it good boils down to "it's good".
[4 of 5 Stars!]