It was okay. Entertaining, but not awesome. Again, this episode was overhyped, being the season's Neil Gaiman episode and introducing the "new" Cybermen. Despite all the hype about the Cybermen getting a new redesign and being "totally reinvented" they're not really much different. Sure they have a new Iron Man-esque look, can move at really fast speeds and can pull off various limbs for fancy tricks. But really, that's what they are, same old Cybermen with a few new tricks. And those tricks, while cool, don't really bring the Cybermen back to the "forboding threat they were in the classic era" or whatever the buzzword of the episdode was. The basic thrust of the episode is an army of Cybermen marching off to fight Our Heroes, just like in the RTD days.
Hell, we even have the same Cybermen theme playing that was used in the RTD era. Which I don't mind, it's a good tune, but when Moffat took over pretty much all music from the RTD era was abandoned and the show started from scratch. We hear the occasional snippets of All the Strange, Strange Creatures, but the show as a new action theme, new theme for the Doctor, new Dalek theme. UNIT's theme wasn't used when they were on the show earlier in the season (and that was used on SJA as well). Yet, despite all this, the Cybermen keeping the same theme introduced for them in 2006 seems very odd.
They didn't really need to use the kids that Clara looks after in this episode. Really, they could have just used any random kids that live on the planet for whatever reason. Yeah, I get it, using Clara's charges gives her a vested personal interest in defeating the Cybermen, but that wasn't really captilized anyway so it seems rather unnecessary.
The "punishment platoon" of losers and rejects was an intersting idea, but again they didn't really do anything with it. Aside from the trope of a disgraced commanding officer making up for past mistakes it was just an excuse to feature unlikely soldiers, like the scrawny guy with glasses or the fat guy who probably never works out.
Oh, and the twist that Warwick Davis was the Emperor? Totally saw that coming.