As a platinum for several years, I got an upgrade in Seoul (Holiday Inn), one in a Holiday Inn at Newark airport, and probably a few more, but this is very scarce compared to the hundreds of nights spent.

Concerning the breakfest, my understanding is that free breakfest is sometimes served for priority memebers, but being platinum does not add anything;
So, if the hotel does not give anaything to a Priority member, it will not do more for me.