I thought Power Girl #15 was an excellent issue of the series. Winick is doing far more with Kara and her supporting cast in his what 3 issues so far than Palmiotti and Gray did in their 12. Which isn't to say P and G were bad, just that they favored a rather static form of storytelling that didn't really effect the characters, grow them, or change them---at all.
OTOH, Winick gives us the first one of PG's supporting cast I can distinguish from the others apart from Terra of course. And he shows us just how tough and resilient Kara is, and how she can direct a battle, thinking through things rather than just hitting. I get Herald, he's just reflexively anti-DC most days, and really, really hates Winick. But the one or two others who share his view on this issue I don't get.
Sure, there are a couple of minor quibbles, like the Kryptonite thing, which may or may not be Winick forgetting she's immune, (though someone pointed out it might also be Max making her think it was hurting her), or the lack of her putting Crash in the middle of the Atlantic, (which upon actually reading it seemed like it was something that would be a lot easier said than done with a Doomsday level guy---recall that Superman tried to get Doomsday into space and couldn't). But on the whole, this issue advanced Kara's story, presented her as not only a mega powerful hero, but one who had guts and brains to go with it, as well as a certain toughness and willingness to do a few not terribly nice things to win.
How the latter plays out with Nikko remains to be seen, though we seem sure to get him as a continuing character and sidekick to PG from comments elsewhere. Though he is one of many hacker type sidekicks in the DCU these days, he works in context of who PG is and what she's doing, and seems an interesting character in his own right.
And while taking the focus away from Terra takes away all of that relationship stuff that was nice and fun, it also allows more focus on Power Girl herself, and on developing her as a hero.
Perhaps not the best issue of the series, but certainly one of them on the whole. It did what it needed to do and moved the title character and the series along, setting up some good stuff for later issues.
Achilles is the kind of evil that hollows out a volcano for a lair, and sends killer robots after his enemies.---Lord Simian