This page tells me over and over to
check the T&C for details.
When I do, I find this under Gold:
Gold Elite Members will receive the following during stays as a registered Gold Elite Member:
A 25% bonus on Base Points earned during the period they are Gold Elite Members. Bonuses will be applied to stays in the order they are posted to the Member's account.
Complimentary high-speed internet access in Member's room.
Complimentary access during your stay to health club or fitness center where available and where the health club or fitness center is owned or operated by the hotel.
Choose a My Way On-Property benefit. Click this link to view the choices at each hotel brand within the Hilton Worldwide portfolio......
And this under Diamond:
Diamond Elite Members will receive the following during stays as a registered Diamond Elite Member:
A 50% bonus on Base Points earned during the period they are Diamond Elite Members.
Complimentary high-speed internet access in Member's room.
Guaranteed reservations availability, subject to the restrictions stated herein, at hotels within the Hilton Worldwide portfolio when paid reservations are made before midnight hotel local time, two or more days (48 hours) prior to intended arrival. RESTRICTIONS: This guarantee does not apply to reservations paid for in part or in full by HHonors Points, free night certificates issued by Hilton Worldwide. This guarantee does not apply to a hotel when that hotel.....