It was fluff, enjoyable fluff but more due to nostalgia (!) for Hearts of Steel rather than the Lovecraft* rubbish strewn on top (really the monsters could be anything). Still, it's readable, inoffensive and infinitely better than the gigantic puddle of shite that was the series lead-in issue. Better than I had expected. It's alright.
Though the cliffhanger does not work: Optimus Prime in this universe did nothing more than appear in concept art in HOS, so the 'HE'S COMING BACK!' means absolutely nothing. Substitute his name for anyone else and you'll see the problem.
*I think it's assumed the readers know who these things already are, so no time spent explaining why they are A: scary, and B: anything special or different from other monsters that possess people.
Suffers from the format of the Infestation crossover, where no real resolution can occur due to the events which need to go through the rest of the titles and doesn't even have a subplot to resolve (which Infestation 1 had). A wasted opportunity as I would have welcomed more from the HOS universe.
I've not picked this up yet - but read Infestation TF #1,2 last night - so this is the last time we see IDW Kup? I'll re read it again with the other issues, could it be that Dan was planning that Kup was the start of the formation of the dead universe seeing that he redirected the bridge from Cybertron to the start of the dead universe.
That's the fan interpretation, though I'm not sure if it's been confirmed by IDW. There's sufficient space in the story that allows them to come up with another origin for the dead universe, if they wish.