I like this model of Carvin and it's got really good specs. I was wondering if it was good for metal and whether the pickups were really as good as it says.

The ESP Horizon that I want has an OFR and locking nut, with EMG's and a neck-thru design, while the Carvin has a set-neck, which I prefer to neck-thru's.

What's your opinion on the Carvin?
Why would you prefer a set neck over a neck through body? As much as I love Carvins I think a Floyd Rose and EMG laden guitar would suit metal (if your definition of metal is incredibly brutal) better than the Carvin though you could technically get the Carvin with an OFR and put in EMGs later....

As I said I am literally in love with Carvins, I like the CT but the DC is by far my favorite Carvin body style.
As far as whether a guitar can do metal well is more or less how much gain the amp has.

Carvins have a good bit of bite as they are, I highly recommend changing out the pickups for something with more balls. Say Dimarzio's Evolutions, drop sonic, or maybe something more rich and harmonic say a PAF Fred, or SD JB, Jazz, 59.
Major of 7 String Legion 7 > 6

Carvin DC747
Ibanez RG2228
Schecter Avenger Custom Shop
and my baby....
Gibson Explorer Studio
Carvins are very versatile and can pretty much play what ever you want to play. As for the pickups, try them out first.
That Carvin is very versatile, and can do much more than metal.

But before you go spend >$1400 on it, what amp do you have?
Roland Cube 30X, though I'm getting a Mesa combo later.

I'm thinking of getting Seymour Duncan JB's. I really like high-output Alnico humbuckers.