I feel as though I should probably have something coherent to say, but I can't seem to find the words.
Any words, really.
... no, on second thought, I have a few.
In all the history of Doctor Who, old and new, we've seen Companions come and Companions go. We've seen deaths on-screen that had harsh impact; we've seen Companions who were left behind and who chose to leave for new lives either on Earth or on other planets; we've seen some who disappeared into offscreen storylines that were never entirely resolved.
In all that time, as far as I myself can recall or find in a quick online search, we've only seen the memory modification trick used once. Once. And it was done by other Time Lords, to Zoe and Jamie, when the Doctor was being taken back to Gallifrey to be placed on trial for mucking about with the universe, not by the Doctor himself.
(If Donna couldn't live as the Doctor Donna -- you know how that storyline could have been saved and made awesome? Go through a few episodes with her in that role, and then have her die. Not even a whole season, necessarily; just a few episodes. Quality of her CHOSEN life versus quantity of the one she begged not to be returned to.)
And while I'm on the soapbox about things we have seen and things we haven't, let me go on record as saying that I hate and loathe and despise the Ten/Rose ship with a passion, because that's JUST NOT THE WAY IT IS SUPPOSED TO BE, OKAY? Check out the reaction to the incident with Grace Holloway in the 1996 movie, if you need non-Rose verification. Doctor Who is supposed to be about adventures and awesomeness and other worlds and times and all sorts of wonderful and incredible things, not an angst-ridden and dramatic romantic soppy soap opera of a love story.
Even more so when it's a bad one. The entire 'here, have a pseudoTen only a human one!' story turn has the feel of a cold dead fish presented to viewers as a fanserving sop that was badly executed to boot.
In short, even the things I loved about this episode are currently washed away by the nausea that's threatening to overcome me at the rest of it. I'm going to go make tea and wait for it to pass. Maybe I'll be able to talk about the good parts tomorrow.