Seems to me that the many people who think D&D botched Bran & Rickon's "death" fall into two camps: The bodies don't look anything like Bran & Rickon The bodies were too obviously fake (as in, don't look like dead bodies rather than don't look like a particular character)
Me, I think that scene was horrifying enough exactly as shown.
To the two points above, I would argue:
re 1. - just what would have been more "Bran and Rickon-like"? Westeros doesn't have plastic surgery, how else could Theon possibly doctor up the miller boys' bodies to make them more "accurate"? (churns my stomach just thinking about it) One thing the show could have done - but would have required some thought in much earlier episodes - is to include some McGuffin - dunno, a particular object (jewelry? pocket knife?) clearly shown to belong to the Stark boys, then have Theon prominently display it after the slaughter. Very cliche, though.
re 2. - The show is already pushing the envelope as it is, could they really get away with showing realistic! corpes!! of LESS-THAN-TEN-YEAR-OLD KIDS!!! on TV? Maybe I'm more squeamish than others, but I really, really did not want to watch a mutilated-yet-still-recognizable child's body dangling on a rope, thank you very much...