It doesn’t make financial sense most of the time to get Platinum or Titanium based PSUs for mining. If you really need that extra efficiency you need to get a server PSU. Those are usually very efficient and reliable.
Most of the decent PSUs are the Gold rated PSUs. Sometimes you can score a deal on a Platinum level PSU however those are rare. Server PSUs is the way to go if you got tons of rigs and noise is not a factory. Especially if you got access to 240V power.
aaaaand..
titanium or platinum is less efficient then gold or silver if you don't hit the peak of the "efficiency curve" of the specific PSU.
yeah you can get gold, but it is "golden" that your load is just about right at the peak of the "efficiency curve".