Who cares which jail, as long as they lock the perverts up?
Some people may object to such a Governmental policy shift on the grounds that it not only legitimizes what many consider to be a "lifestyle choice" or a mental disorder but also becomes another weapon that criminals can use to manipulate the system when they are placed in that system for the express purpose of limiting their ability to manipulate the world around them.
Regardless of what body parts you have a surgeon hack off or add, every cell in your body contains DNA that specifically identifies you as male or female. Therefore, these gruesome surgical procedures don't actually change your sex, they are merely exercises in carpentry and remodeling if you will, without changing the essential foundation or framework of the house..
So, all of this ultimately comes down to it being essentially the state of mind that the person is in which determines their 'gender'. and so which prison they are sent to. Some find it objectionable to make such determinations based not upon physical reality but on a person's state of mind.
We already have a precedent of clinically deranged criminals being sent to prison mental hospitals, but this circumstance will be dictated by a clinical diagnosis of insanity. Here in the USA the American Psychiatric Association removed homosexuality from a categorization of mental disorders a few years ago (without the usual scientific studies and factual rationale....it was an entirely political move).
Therefore, we now have a situation where a criminal's state of mind and / or lifestyle choice is allowed to dictate their type of incarceration but it's not being done on the grounds of it being a mental disorder. Many view this sort of thing as being an erosion of the severity of the penalty being served (a woman's prison might be viewed as preferable, on numerous levels, to a men's prison)