Getting back on topic, it seems to me that the best transcriptions are always going to be from people who are interested in the subject ? Ancestry have used a variety of sources for their transcriptions, including
genealogist societies, and volunteers in the WAP project. Another popular site, The Genealogist, has a limited number of census returns which have been transcribed by volunteers, allegedly with a better accuracy. Find My Past appear to use their own transcribers, but they appear to be a little cagey over who they are.
To be honest, I have a lot more problems with mistakes made by enumerators than with mistakes made by transcribers
