"Heather Harper sings beautifully though in an 'inauthentic', operatic style" ... I was interested to read that, because my first reaction on hearing track samples of this recording was "but this is not an opera!"
The reviewer's comment reflects a chronic problem with Big Companies' recordings: they go for "big names" by reflex, regardless of suitability.
I have just bought Linn's recording of this work by the Dunedin Consort under John Butt, and it is a must. The band, the conductor and the singers are all excellent. Joanne Lunn makes an interesting comparison with Heather Harper; she brings "I will follow you" to life, and her "floods of tears" seem real, while Heather Harper seems merely to have turned over the page. Again on the basis of a few track-by-track samples, so not a proper comparison, the OAE under Stephen Layton on Hyperion seems to split the difference; more life than the Decca/Britten recording, and at least they know it is not an opera.
So while I can't give a proper comparison, I'm glad I bought the Linn/Dunedin, will consider the Hyperion (if the price comes down a long way), and I have no inclination to buy the Decca/Britten performance.