Given that the turbo has an intercooler and a waste gate, I'm wondering if it actually does matter.
In most cases, the turbo has plenty of spin to get the air to the proper pressure and temperature. Higher inlet temperature means it has to pump in a bit more air, but it should have the headroom to do that. Whenever the waste gate is open, I wouldn't think the inlet temperature is going to make any significant difference.
I guess at lower RPM where the turbo is still spinning up, a lower inlet T could help a bit, but I doubt anyone could actually tell the difference.
Maybe I'm missing something about the way turbos operate. Inlet temperature would seem to be more of an issue for a NA engine than a turbo.