*Complications: painful, nasty, and potentially unpleasant complications are way too common for my liking. I've come to the conclusion that the surgery compromises the integrity of the body so badly that the risk of complications is excessively high. Furthermore, once a vital part of the body is weakened by incisions or tearing it can fail months or even years later even if it heals up initially.
*Possible loss of orgasm: related to the above.
*Regret: in my case, related to the above. If I could just take a pill and wake up with a vagina I wouldn't hesitate but I know I'll have regrets if I spend the rest of my life with recurring fistulas, chronic infections, or unable to enjoy intimacy as far too many post-op MtFs do.
*lack of long-term data: the available studies on the long-term outcomes of these surgeries are rife with problems and don't really come to any clear conclusions. How often do complications arise? Will a neovagina eventually prolapse 30 years later and cause me an agonizing death? Will I only get 10 good years as a woman before I start losing depth? I just don't know and neither do the doctors who perform these surgeries.
For my part, I decided not to get a vaginoplasty until it's a life-or-death matter for me. It's too risky. I'll make do with an orchi for now because even though I hate having male parts, I can kind of deal with it.