Today, in what may be called the period instrument movement, everything is too often rushed. If yopu find the Klemperer is what your prefer for Bach, go for it. I would like to hear it, but I must confess that Bach's vocal music does not appeal much to me, although the Brandenberg Concerti put a huge smile on my face. I think it's because I feel Bach's vocal writing has an instrumental approach where Händel's writing seems to flow more naturally. It's all a matter of personal taste.
I see that Bernstein conducted an abridged St Matthew Passion. His cast doesn't impress me, but I don't like his work in baroque music. He seems happier in romantic, late-romantic, and contemporary music.