That guy does have a pretty sweet set up there.. what would I have to mod to fit a 360 up top?
Not much modding is required to mount the 360 rad up top. there are four holes in the top of the case that are made for a 240 rad. used those for main support, only mod i really did was drill one more hole under the power button/other connections fixture for support.
Part of the radiator is blocked in the front. You can cut away some of this metal to provide better airflow, but I chose not to. It is not possible to mount a fan in that location, and it does not completely block the airflow there, so I left it intact.
There is also plenty of room for cable routing event with the radiator in place, so no worries there. If you are going to mount a rad on the rear inside of the case you will have to use a 120, the one i used is actually a bit large and ended up having to drill new holes to mount it.
With the 360 and 120 radiators cooling an i7 920, NB, Vreg, and GTX 480 it is absolutely fun. video card is cooler under full load than it was at idle with the stock cooler. everything is overclocked, and surprisingly well. with a 970 a 580, and probably a better motherboard than i have you would run much much cooler than I, even with higher overclocks. If you only have water blocks on your CPU & GPU I see no reason to have more radiators.
To answer your question about if it is worth it.... How much do you like working on your computer? the more you enjoy it, the happier you will be. It takes a load of time to set it all up. Liquid cooling is great fun for me. not for the pocket book though