I had a couple of very small bits of Ocean rock in my nano tank just propping up some live rock, I was going to rip it out until the emerald crab decided to make his home in one of the big holes. The hermits seem to like hiding in it at night and the turbos have been all over it. So it can't be all bad, bit stark in colour though and isn't porous at all although it does have huge holes so must hold some good stuff (increased surface area).
As Ozzie says I think it would be pretty disasterous to use too much in your tank but I am going to keep a couple of bits just to see what it does over time appearance wise.
As for a journal dayz I have been resisting the urge to start a journal as my tank is 5 weeks away, but I do have my light unit now and I have 2 huge pieces of Reef Bones that I couldn't resist at Coventry Aquatics. Ones a huge plate coral about 15 inches diameter and another is a piece of branching coral that looks like the crown of a tree and will be used upside down to support tunnel through my live rock pile. I also confess to scaping them on the conservatory table with a black backing and taking a photo. So if you post your pile of rocks, I will post mine.