A study on post-op regret based upon how the patient initially obtained a transgender diagnosis would be highly beneficial. I imagine that those who entered the process via quick informed consent would have a far greater percentage of post-op regrets.
I fall somewhere in the middle on this subject. From what I've seen, gender issues are so destructive when hidden that by the time someone seeks treatment, they are often also suffering from other issues - depression, stress, suicidal tendencies perhaps, family rejection, crumbling marriages, financial woes etc. These have to be addressed too, and with quick informed consent there is no attempt to even identify, let alone address, these problems. Quick informed consent also allows those who are misdiagnosing themselves access to some life-altering treatments, and let's face it, who hasn't misdiagnosed themselves by looking at the internet and talking to equally ill-informed peers?
But on the other end of the spectrum, gatekeeping (which, as I understand it, is where the therapist personally has to "approve" the fact that the patient is suffering from gender issues - i.e. the therapist is no longer objective, but subjective) is equally bad in that it's an archaic roadblock based upon outdated information. We know far more about gender from a medical perspective than we did when gatekeeping was the norm, and it is unnecessarily cruel. Imagine having a patient with a broken leg "prove" that he can't walk before being given any treatment whatsoever? An extreme example, but it conveys the point.
True informed consent is, in my mind, the only way to go. You're having a professional double check that you're not way outside the diagnostic spectrum, slow the process down a little (because we all get excited and want to get started on the medication as quickly as we can), and encourage a little self-examination to make sure you understand what you're getting into. There is nothing wrong with having a few sessions with a therapist to make sure you're starting out on the right track. It's hardly a huge hurdle to overcome in terms of time or cost (and if one can't afford a few hundred bucks for a few sessions of focused therapy, how does one expect to afford the far higher costs of successfully transitioning?)
Of course, I don't advocate for one way into the system either. There are people I know who have intelligently and thoroughly researched their condition and options, and who would benefit from quick informed consent. There are others who have bigger problems to worry about that gender, or who have some crazy misconceptions about what transition is, who could use some hardcore gatekeeping. Most of us, though, seem to fall into the middle where true informed consent is appropriate.
I'm just starting HRT and I'm making sure I'm going to continue visiting my therapist throughout; I want to make sure that I have someone keeping an eye on me so I don't end up in the "regret" column when all is said and done. I don't want to ever detransition or have any regret - to me, that is a sign that someone (me, the therapist, doctors, whoever) made a mistake. And as with all medical treatment, mistakes really should be unacceptable. If one takes transition at a safe and monitored pace, the chance of making a mistake is minimized.