I'm that anonymous commenter on io9 who you quoted. Your examples are fair points even though the photos and song didn't bother me. But others have been unfair in their zeal to slam Let Me In. Let Me In is being attacked both for being too much like the '08 Swedish movie and for deviating too much from it. Even when some of those same deviations are closer to the book.

Examples: LMI opening with a police investigation after terrible things have already transpired rather than LTROI's slower build. Abby's normal face is doll-like and feminine. (I'm not saying that actress who played Eli in LTROI is not that in real life, but she was intentionally made up to look more androgynous than she really is.) Abby's attack mode morphing, monster-like face and sharp teeth. Abby's female victim drinking her own blood. Abby wearing a heavy metal tee shirt.

All of these things from the book that made it into LMI but not LTROI have been bitched about by loyalists (who assume that they are Americanizing additions) and just want to punish LMI for having the gall to remake LTROI.

I own both the novel and the Swedish film and I think that the first movie is an improvement on the novel; similarly, LMI is a further improvement. Unnecessary characters, subplots, and backstory are stripped away in each adaptation, resulting in a more focused story. (However, if I were to change anything about LMI, I would have Abby very briefly explain something that is a momentary shot in LTROI. You, know the one everyone talks about.)