We recently stayed at both hotels. The Tru by Hilton Hanoi Station is really new so the rooms are nice. The hand sink is located outside the bathroom, there are only USB-A ports for charging by the bed and there is no hand wash in the hand sink, only hand lotion. Noises from the station could be heard from our room on the 12th floor. Breakfast is okay, pretty much like at Hampton Inns. From there, it is walking distance to the famous Hanoi Train Street (South Train Street) which was worth a visit. The Hilton Garden Inn is an old hotel but the breakfast buffet is much better. As others have mentioned, they give diamonds drink vouchers to be used in the bar. From the hotel, we walked to the Old Quarter, Dong Xuan Market, etc.