Jarrett's hot performance by modern piano
It becomes hot performance from the fugue of A major, though the first half of 24 preludes and fugue are performed, as it were, indifferently. The sixteenth notes of the A major fugue is brilliant. The fugue of the last B minor is a masterpiece. I think his Well-Tempered Clavier Book 2, played by harpsichord, is better.

A fine recording
Keith Jarrett is rightly lauded as one of the finest Jazz improvisers post 1960. That he has recorded Handel, Mozart and Shostakovich in addition to this album of Bach indicates that he has reached a level of musicianship that few will ever equal, let alone surpass.

These recordings were performed on a modern Piano. However of course the modern Piano did not exist when Bach wrote the pieces. So Jarretts interpretation has a narrow range of expression, reflecting the fact that originally these pieces were most likely performed on Harpsichord.

Off and on I've been listening to these recordings for 15 years now, and as an amateur Pianist myself have found them invaluable when trying to interpret the original sheet music.

The ultimate word on the WTK Bk. 1
Absolutely reference status - technically perfect, wonderful articulation and no exaggerations and mannerisms. Overwhelming playing, decently devoted to the work of JSB. Recommended for all teachers and learners.

I went without food one day to own these recordings...
When I was younger and had less money. They were worth it.

Strong Interpretations
Keith Jarret's Bach playing is remarkably good. These are not overly interpreted performances, but rather understated, no frills Bach playing in the style of say, Richter.
You'll find very little to dislike in Jarret's playing. He plays with joy and yet a reverence for these revered and oft studied works. His technique is more than adequate, his phrasing is right on the money, and his tempos are very conservative.
Overall, I'd say that these performances hold up well with the best available recordings out there by classical pianists such as Schiff, Hewitt, Tureck and Richter, and therefore I highly recommend it.
Enjoy