Hi all. I'm going to travel Asia and Europe this year. Next year I will travel all USA.

I have the following questions and I would be delighted with as much help as possible and it will be highly appreciate.

Hilton hotels in USA:

how often are you giving access to lounge as gold member? how about room upgrade? Only when booking at Hilton.com, how about priceline, expedia and so?

Is there difference between gold and diamond? are diamonds treated much better in usa hiltons?

Hope you can help me