As Horowitz's disc of Scarlatti sonatas is one of my favorites, I'm curious to know why you don't care for his approach.
I agree with many of your comments about an overly Romantic, self-indulgent style and a heavy touch being detrimental to the spirit of the music, however I'm wondering if you've heard the disc I was referring to. On that album Horowitz plays many of the sonatas in a scintillating fashion with considerable forward movement and often exciting flair. Some of his concert performances on disc and as seen on YouTube are slow, rhythmically flexible and "inward," for sure, so I can see that they're not to everyone's taste.As to being informed about Baroque practices, the liner notes for the original LP claim that Horowitz consulted extensively with Ralph Kirkpatrick while preparing to record as he wanted to be stylistically informed and "correct." Whether he achieved that you'll have to decide.Perhaps you'll fare better with Milkina...
I don't see why you don't like Pletnev's I personally like his recording of the Scarlatti sonata cause of the way he take some liberties and adds notes and trills to certain parts of the sonatas where it is suitable and i find his recording very clear especially the d minor sonata .