Like this wholes series of Angela Hewitt's Bach series from Hyperion, this is a sublime performance and recording.
The obvious comparison for Hewitt is with Glenn Gould - both are Canadians who play Bach on the piano rather than the harpsichord. Both are masters but they are very different. When I listen to Glenn Gould, I marvel at his genius; when I listen to Angela Hewitt, I marvel at Bach's genius.
What many may not realize was that Angela herself is responsible for these recordings. She was having difficulty getting a recording contract and initiated the recordings herself. She even writes the liner notes brilliantly. The major labels weren't interested but Hyperion - a small specialty audiophile label picked them up to the benefit of all. Hyperion also records Marc-Andre Hamelin - another wonderful expatriate Canadian pianist. Hyperion has had some legal problems of late and is strapped for cash so support them if you can.
A note regarding Amazon's classical music listings. There simply is not enough information to know definitely that you are getting the CD you want. More information should be provided about the program and the label - information that would be on the CD liner. In particular, it is virtually impossible to know if you are ordering the regular CD or the Super Audio CD.