I recently ordered an Earvana shelf nut from Feline (Jonathan) and having done a gig with it, I'm a happy rocker.
Open chords are now dead on, or at least good enough for my ears, where before they were horrible. The whole neck sounds pretty good. Right up at the top of the neck (17th fret upwards), I'd say the intonation has got worse. The 19th fret comes up sharp. But since I don't play chords up there, it's not a big problem.
The only real downside is that I can't get the D string perfectly intonated, and the saddle is at the end of its travel. It's only really noticeable if I play the intro to Sweet Child o' Mine... the lower D clashes with the octave.
Anyway, all round a good buy I reckon, considering how poor the intonation was before. That said, I had the frets stoned at the same time, so I don't know how much of the difference is from that.