Well I have built 4 systems now with 3 Phantoms and 1 Corsair 600t.
And my verdict goes as follows:
Corsair:
Quality wise the best. The paint is really nice, the cable gromets are bigger and stiffer, there is more than enough space behind the motherboard tray to get rid of the biggest cables. The side panels are taken of very easily, overall the case feels really solid. An overclocked i7 overheats in this case. I am not happy with the out of the box airflow, it runs too hot and the motherboard overheats too (60 degrees+).
The 2 200mm fans generate some noise, more than the Phantom.
Phantom:
Slightly less awesome cable management but still good enough nonetheless. Awesome finish. If you outfit it with all the fans you get supreme cooling. I have never had a case that is this silent (if you outfit it with some silent fans) and this cool at the same time. I love this case so much I ordered all 3 colors! If you tweak the fan controllers you can get a very silent and yet very cool system, cooler and more silent than the corsair.
My personal opinion is that if you want a 'business' PC that has to compete to a MacPro in Looks and quality than the corsair is your thing, everything is 110% on that case.
If you want a rig that can do some extreme overclocking and gaming I suggest the Phantom.