I voted for the middle ranking. The episode was entertaining for a bit, but seemed to drag out quite long. This might be one of those stories that's not interesting enough to fill a two-parter. Some observations/comments in no particular order:
-As with so many of you my initial reaction to the Flesh was to see it as a solution to the killing in The Impossible Astronaut, but I expected it to be more subtle. I thought the Doctor's clone would not be seen or hinted at anymore beyond the first Doctor-Flesh touching and then pop up later in the season. When it became obvious (and oh! did it become obvious fast) that the Doctorganger was going to show up in this episode, I started to think it less likely that this would be the Astronaut solution.
-The cliffhanger was too obvious too soon in the episode, complete with final line of dialogue.
-Rory seems to be behaving oddly. It could be (a) because he has so little to do usually that anything he does seems out of the ordinary or (b) an in-story reason. I got the vibe that he might somehow be under the influence of the flesh, beyond just caring for the gangers. For example, in the scene where the gangers and `originals' meet, just before lady what's-her-name comes in and shoots the ganger, there is an odd moment where the ganger Rory's so protective of (geez, I really connected with those characters... what was her name again?) grabs his hand in a weird way and Rory pulls back and looks surprised. I think there was a similar moment earlier in the episode. Just confused acting or relevant to the story?
-Speaking of what's-her-name shooting boss lady. Sigh. Why do people keep writing stories where the drama is created only because some people are acting stupidly? What did she have to gain by shooting the ganger? Either she really sees them as a threat and she should take them out all at once, or, preferably, she calms down and tries to figure out a solution. This is just lazy writing, creating problems just because the characters behave in a dumb way.
-On the plus side, even though I can't think of a sci fi show of the top of my head that hasn't touched on the topic of having clones/doppelgangers/the same characters from past or future/or any other variation on the same theme, still I think the bulk of the episode tackled it in an entertaining way. Nothing special, but entertaining. Up until the point where things artificially escalated into war!!!111!! I fear to be bored next week, please show, prove me wrong.
Is it just me, or is this season missing some of the energy, some of the frizzle and sizzle of last year? Last year got me into the show, I can't help but thinking that if I would've tuned in this year as a one-off viewer, I probably wouldn't have come back for more. Don't get me wrong, I'm still entertained by the show, but that undefinable something that gave the show its edge (and pushed me over the edge into becoming a regular viewer) last year, seems to be missing for me now.
ETA: The acting of some of the extras, especially that ganger Rory's going after (was it Jennifer?), was a bit jarring as well. A bit too much whining, especially in the "photo of the little girl" scene.