Personally, I like what they did with it in lieu of totally screwing it up.
I mean, they could have said: "Let's revisit Dark*Matter, but we'll reimagine everything from the ground up! All new content!" Which, frankly, would have probably turned me off unless they had me write it. ;D
The core of Dark*Matter is reprinted. Mostly, I feel, because they got it right the first time. Some of the things I didn't like didn't really make the cut, even. (Kinori, Mothmen).
That said, I'm not going to use 99.9% of the book.

The magic system is D20 Modern's magic system. They included new spells that mimic some of the traditions (Wings of Icarus, a short fly ... all of the Vodoo stuff) but they're either Mage or Acolyte spells. The major traditions they did as X/Day Class Ability PrCs (Hermeticism, Diabolism, Monotheism, etc.
It lets you, fundamentally, play Dark*Matter with the D20Modern rules.
(The Sand Slave stuff does use D&D rules, which is sloppy work, but in my own writings I'm guilty of the same thing ... I just include a side bar explaining the D&D nonlethal rules. I like those better, they offer more options, but I don't accidentally include material based on those rules without explicitly stating that they are a variant from the D20Modern ruleset.)
They have one absolutely GOLDEN (GOLDEN!) feat in there that takes the utterly ick Vancian magic system and makes it frickin' usable ... Blood Magic. It's a Diabolism gag, but not restricted by tradition, so you could make the flavor text anything you want ... you can cast a spell without using up the slot by taking 2d6 x Spell Level damage. Boom. You go from straightjacket vancian system to options and choices ... you're not out of spells, you're out of FREE spells.
I still prefer certain other systems, of course, for the magic of Dark*Matter, but that feat alone, I feel, makes what's in the book quality junk.
Well, other than the PrCs, which I feel are totally junk. I hated the concept in Polyhedron and I hate it even more now. Personally, it's a design cop out. They took, essentially, the spells from the original text and turned them into X/Day abilities to skirt around the fact that the vancian system couldn't handle it ... and, frankly, neither can just making them X/Day abilities available at certain levels. It's inflexible, flavorless, and cludgey.
I mean ... given freedom to create new game systems would I have done the magic area of the book differently? Yes. Would I have accidentally used the wrong rules for nonlethal damage? No ... but only because I would have, again, introduced a new system.
The book also contains some of the better (and not so better) items from the Dark*Matter Arms and Equipment Guide, so, it gives some new D*M equipment.
Some of the reprinted text isn't just ... they adjusted alot of things in the Welcome to the Hoffmann Institute section ... introduced Department 7 to toe the standard, but restructured the departmental section some so everybody could be from D7 without it being a cludge to get the team together on a mission (before you had many different groups with different goals who wouldn't really be sending team members out to do gung-ho cowboy antics and would instead handle it with small focused teams of their own ... so every PC group was a "special case scenario".)
There's more information there to introduce and interest the PLAYER ... which is why, in the end, I bought the book. I left it at the Game Haus so the others could pick it up and fondle the textured cover and read the introductory elements and become interested in playing ... because I haven't run a tabletop Dark*Matter game in over a year ... and I want to.
It's a toss up ... if you have the original books, then you've got good solid flavor text in your hand already. I've long urged people to go out and pay 5 bucks for the Dark*Matter PDF, because that's probably the best value out there in gaming fluff for your dollar ... the original book didn't contain too much in rules, so this book didn't need to include too much in new material.
Did they use the existing magic system of d20Modern? Yes, but did anybody really expect that they would do differently? They have a system standard to adhere to now and I doubt they'd have let the writers go forth doing a new system. They did add one feat in there which opens a back door onto the existing system to make it more flexible ... little diamond in the rough there.
My major complaints? That they didn't sidebar D&D style nonlethal and just admit that they too don't like the Modern nonlethal system. And the PrCs for the magical traditions ... those are utter crud, IMHO, and I'd never use them in a game.
--fje