SPG Gold used to be worth more, when in-room internet was generally not free. In-room internet was offered as a welcome amenity choice, and could often save approximately $15-20 per night. There weren't any significant benefits which replaced that. Benefits such as extra points earned have already been mentioned by others in this thread.

SPG Gold also contains some benefits which are hard to quantify or predict. On occasion, SPG will provide promotional opportunities which target Gold members. In 2013 there was a requal gift offer to save 25% off a point redemption on an award stay, up to a Cat 6 hotel. That saved me 20000 points on a 5th night free redemption! It is hard to know what promotions Starwood will offer in its limited independent future, however there might be some great offers next year (or maybe not). Room upgrades to higher categories, higher floors, and better views, do occur, and some properties recognize SPG Gold guests by providing other benefits. These occasional benefits are generally small in nature, and not worth mattress runs.

Without knowing more about any new future benefits or promotions, I would not spend $200 or more in mattress runs to attain SPG Gold. If in the US, getting the American Express Platinum card would provide SPG Gold with several nice benefits outside of Starwood. That is the route I would go if I wanted to attain SPG Gold for 2016, and was short by more than a night. The Amex Platinum card would likely not help for any future potential status requalification offers though.