The first review is for one of the 5-pack Combaticon (Bombshock) set. As the video shows, it turns out the set is essentially one scout class toys with 4 legend type figures that do not have a robot mode. The combined robot is a pretty good looking toy but not sure if worth the estimated $20 price tag. The 2nd and 3rd videos shows off the 2-pack sets with Searchlight with Backwind and Smolder with Chopster. OK figures, still not sure worth the price (around $10).
Overall, the video reviews seem to demonstrate that the basic idea behind Power Core is one scout sized figure that can interact with two types of legend sized figures (mini-con). Those two types of mini-cons are either the weapon type or the combiner type. The weapon class has a robot mode, the combiner class does not. Any scout figure plus 4 combiner mini-cons results in one combined robot. This idea does seem scalable (say deluxe class combining with Scout) and indicates a bunch of possibilities. For now though I think I will take a wait and see attitude towards the line.
Update: Peaugh posted a third Power Core view so made slight alterations to text and posted the additional review.