I like the idea of original instruments. It is a different sound and texture. It's the reality that I don't like.
Yesterday at the Zurich opera I saw Handel's Giulio Cesare in Egitto played on original instruments by a group calling itself La Scintilla. They relate in some way to the opera orchestra. They played natural horns in a couple of pieces, once with a stereophonic effect that worked pretty well, and once with a soloist who stood on the stage with the singer. He stunk. He blooped about every third note.
If you want to play on original instruments, fine. But could you please learn to play them first. Could you, for instance, learn to play them in tune. The performance standards just drop off too far for me.