I began working with this build and found that I need to be able to apply pressure. I found out that if I cut the ghosts (two ghosts = 400 gas, one ghost = 250 gas - that's a lot of time saved) I can do a marine/marauder with stim and cs push before colossus can hit the field. Ghosts are a large gas (read: gas is time) investment and limits your options early.
As for lategame, I don't think there's any excuse for not using ghosts in the lategame.