I've only recently become fully acquainted with this case, and that's largely through the exhaustive - and at times exhausting - videos of Rich D Hall, and a few others available on Youtube. While I don't believe Mr Hall is as objective and analytical as he purports to be, he does highlight so many inconsistencies and oddities I do struggle to accept the 'abduction' theory. My instincts lean towards Maximus Otter's summation of a few pages back, but that's only instinct. A couple of things that particularly tweak it are:-
The McCann's consistently detached behaviour. I don't read it as being compartmentalised or tamped down in order to cope, as surely even then there'd be subtle indicators; surely you can't entirely bury trauma that intense? To me they seem distant, remote, disconnected somehow, their tones emotionless, their expressions flat. In one interview I saw they were holding hands, but in a static, lifeless way that felt more like they were doing it for the sake of appearances, and not for genuine mutual comfort. On some unconscious level they feel off to me, but that's entirely subjective.
The way they refer to Madeleine. As noted by someone earlier - I regret I can't think who - they have a habit of talking about how they're feeling, and how they felt that dark evening, but never acknowledge their daughter's feelings. True, you have to take the questions and interviewer into account, but it still seems awry, I still struggle to believe it possible to wall off these things so completely. Adjacent to this is how they describe her: always her appearance, and always as being 'perfect', never, to my knowledge, her personality, which even at such a tender age she would have; basic likes and dislikes, moods, and so on. It's almost as if they couldn't ever see past her surface.
One last thought - lies have a serious tendency to snowball. Once a lie's been told, it has to be maintained, for the moment it's dropped could well be the moment it's found out. Many screwball comedies have been built around this very concept. Could you keep a lie going for more than a decade, in the public eye? A big enough one, with serious enough consequences should it be rumbled, and with the right help - like a powerful PR guru and a predictable press - yes.
My instinct is that Madeleine McCann died in the room, a tragic accident occasioned by serious neglect, and possibly earlier than the purported time of her disappearance. Most likely in desperation, her parents concocted an abduction scenario to cover themselves, a lie that snowballed, and is still snowballing, and may well continue to for some time to come. I stress, though, this is only supposition, one person's impressions.