I'd say the Raven looks better, but it's all about personal preference.
Are you ever looking to Watercool? The Phantom lends itself to watercooling better than the Raven, but the Raven is leagues ahead on aircooling. It also has a window over the lack of window in the Phantom.
I'm pretty sure Silverstone's build quality is better than NZXT's as well, but can't comment from experience.
If it were my choice I think I'd get the Raven for air cooling, and a Shinobi XL or Elysium if I was looking to watercool.
kd