I've had three guitars from ESP - a Ltd JH-600EC, an ESP Standard FR-27, and an ESP RZK-II.
The one I couldn't gel with was the FR-27, I was always wondering why the fretwork was so poor and why the guitar felt so horrible under my fingers. Looked really kickass too, with the scalloped frets from 24-27 and the Horizon body shape without the goofy 12th fret model number that I absolutely hate about most ESP guitars.
The Ltd JH-600EC, on the other hand, is a keeper. The 600 series, which is the top end Ltd model artist series guitar, is equivalent to the 1000 series. Very good fretwork, very good fit and finish. Guitar is wonderful to play and sounds excellent. I'm very happy with it, and if I was gigging, this is the guitar that I would use because it fits my price to performance expectations to a T, and I wouldn't be crying if it got a bit reliced. Might even look classy on an axe like that.
The thid guitar, the Richard Z signature, on the other hand, blows the Ltd away, and I don't say that lightly. Everything about the guitar screams premier quality - the excellent fretwork and action, the body paint, the fit and finish. And sonically, it is indeed superior, I don't know why else two guitars with the same bridge pickup (EMG 81) would sound so vastly different. The ESP just has so much more girth and body and power behind it when you're palm muting or chugging. And it's really a joy to play: at the risk of sounding overenthusiastic, it almost feels like the guitar assists you with your playing. Just that damn good.
Of course, I would never take that guitar out of the house or for a gig. If it got damaged, I'd be beside myself. But as a recording machine, I'd pick the ESP every time.
YMMV.