The main benefit for Gold over Silver is the daily food and beverage benefit ($10 to $15 a night or so, depending on the hotel). If you are going to eat breakfast in the hotel anyway, then the card will pay for itself with this credit after ten nights.
A secondary benefit relates to the points earning. Gold status earns more per dollar spent than Silver, and the $95 credit card earns more per dollar spent at Hilton than the free card.
If you are going for the $95 card and want the sign up bonus, just apply for the new card rather than upgrading the old card. You can have both cards.
Also, before your trip, check for Hilton bonuses - there is often a "double points" promotion, or a promotion that provides extra points per stay or per night. You have to explicitly register for this type of bonus.