As with his recording of Dido, Pearlman's instruments may be authentic, but he instructs or allows his soloists to belt out their lines with all the tact of opera in the full throes of Wagner. For those who swoon at the sound of the full throttled, warbling operatic voice, this is the recording for you, otherwise, stay far, far away.
The voices entirely overpower any sense of ensemble -- which is to say, the "authentic instruments" are thoroughly dominated by the soloists.
Besides that, these performances really add nothing new. They are conventional in every sense of the word.