you'd probably be better off asking this somewhere like gearslutz.com, but i'll give it a shot.
unless you have extremly expensive speakers and a perfectly treated room, mastering is next to impossible. there's a reason that mastering engineers make the big bucks, and that's the absurd amount of money that they have to spend on gear. also, you need to have crazy good ears.
i've messed with t-racks, and in my opinion (and the the opinion of virtually every pro audio guy i know) it's a piece of junk. I've never used ozone, but i'd imagine it's probably pretty much the same.
if there's something wrong with your mix, FIX IT. relying on mastering to make your mixes sound better is a really really bad idea. mastering is there to give different mixes a sense of continuity, and to correct for any inacurracies that there may have been in the monitoring setup when mixing. for this reason alone, mastering on the same systems as you mixed on is a big no no. you'll often end up adding to the problems that are already there.