Well I've owned the Phantom for about a year but just yesterday I received shipment of my h110. Sadly, it has been a complete pain in the ass installing. I've been wasting my entire work day trying to look for solutions as to how it will mount. I upgraded from the H100, so I've done this before, but the wider radiator and bigger fans make mounting to the pre-drilled holes impossible. I'm going to see if using the mounting brackets helps when I get home today, but I don't have much faith.
I'm a little disappointed no one else replied to this thread, this is exactly a question I had been looking for before I bought the h110. Everyone already says it can fit, which technically it can, but it doesn't mount easily. I had the same problem with the H100, it doesn't line up with all the pre-drilled holes on the top of the phantom case, but it still mounts to enough of them to work.