They are better off in Canada than they are in a good number of countries including the US but it isn't completely trouble free.
Especially considering how in order to change your passport and driver's license in the US you only need to show a single paper from a doctor about it (you don't even need SRS). Rather than the requirements of an affidavit amongst other papers in Canada. So in the case of the m or f on legal documents, it's somewhat easier now in the US than it is currently in Canada.
I may be misinterpreting the laws in Canada, however, since I don't live there and laws are often in flux or have loopholes not normally shared. But I was reading Article 71 of the Quebec Civil Code, which requires of individuals seeking to legally change their gender to be over the age of 18, be a Canadian citizen and have undergone surgical modification to remove reproductive organs (which to me is what constitutes sterilization).