1. The whole parallel universe thing could've been played out in far more detail. What we got was the Mickey/Rickey bit, and that was good, and "Rose is the dog" was also a good laugh. But there could have been more! I posit, then, that the lame "DE-LETE! DE-LETE!" catchphrase was thought up and hollered out to show that the Cybermen were this universe's version of the Daleks. Every universe has a bio-cybernetic scourge that likes to holler, perhaps?
2. And if that were the case, then that explains and justifies the whole "I'M-GET-TING-MAR-RIED-IN-THE-MOR-NING" Cyberman bit, even if the scene stunk on ice. I mean, that scene was pretty much saying "Hey, gang! Remember how we made you feel bad for the Daleks in the last series? Well, we're gonna do for the Cybermen now what we did back then in Dalek!" Only this time, well, it didn't work. Too presumptuous and contrived. SO-COLD-SO-VER-Y-VER-Y-COLD-NOW-IT-IS-YO
3. And speaking of parallel universes, wouldn't it have been cool if Mrs. Moore had turned out to be that universe's version of the Doctor? I think so. From the tunnel scene on, I was kinda hoping that'd be the case. Unfortunately, I'm sure the only way that would've happened is if a second spin-off show was in the works. That way they could shamelessly drop "MRS. MOORE & ME" plugs in between Torchwood mentions. Because, hey, Torchwood.
4. The Doctor should have tried at least once to thwart a Cyberman with gold. The cliffhanger took place at a posh estate, for crying out loud, there's gold to be found everywhere there. (Sure, the oldschool Cybermen were susceptible to gold dust, which messed up their ventilation systems. That's logical. But somewhere along the line gold in any form became Kryptonite for the Cybermen. Heck, d'you remember Ace taking Cybermen out with gold coins and a slingshot? Of course you do. Oh, we liked Ace.)
5. The entire Discovering Jackie scene was hogwash. Oh, sure. Pete and Rose wade through zillions of Cybermen, only to be stopped at the end by the very person they were looking for. What incredible irony! And look, she recognizes them! Wow! Here, this is how the scene should have gone:
PETE TYLER: Oh no, I ran afoul of a Cyberman!6. Mickey's send-off was kind of nice, though. I'd grown to like him as a character, and I enjoyed watching him realize it was up to him to shake off the Tin Dog stigma. Even if he just up and ran off to Paris without first checking on his Gran and FIXING HER CARPET. Idiot!
PETE TYLER: What?
PETE TYLER: Jackie, is that you?!
PETE TYLER: You can't be Jackie! You can't!
PETE TYLER: Oh! Ha! Good one, Bill.
7. Mickey's act of heroism was great, and the scene was built up nicely, but the climax was ruined by having the doctor shove the cellphone, which just has the Inhibito-Destructo Code displayed on its screen, into the Convenient Cellphone Communications Port What Controls The Entire Cybermen Army. What, was typing the code on a keyboard a little too plebian or something? And while we're at it, let's just upload this virus to the alien mothership using my Powerbook. Bah.