I'm surprised to hear the claims that SPG Gold is "worthless." Guaranteed 4pm checkout (except at resorts) and an "enhanced" room -- which in my experience has often meant a true upgrade of 1 or more categories -- seems to me worth something.

However, I fully agree that trying to earn SPG Gold via stays is sub-optimal. There are periodic promotions (requiring no stays at all) for Gold, and both of the benefits noted above are available to quasi-elite Preferred Plus members, i.e., people who hold the SPG Amex.