In order to receive Five Diamonds, rooms must not only be clean and luxurious, but include specialized design features, valet dry cleaning, 24-hour reception, separate enclosed areas for the toilet, sheets with over 400 thread count, legitimate artwork on the walls (no framed museum posters here), and some sort of decorative ceiling, among other things. The entire process is laid out in a 41-page guide that you can peruse before bed tonight.
The main problem with the Diamond system, though, is that it requires the property to provide televisions in the rooms and a swimming pool just to get about Three Diamonds. And while exceptions are made -- like for the pool-less Plaza in New York -- many high-end hotels that think guests should do things other than watch TV on vacation get left, like Taylor Swift, without a Diamond.
Forbes inspects around 1,000 hotels a year and awards only Four and Five Star ratings based on a titanic, 800-item checklist that covers everything from the hotel to the restaurant to the spa. We'll save you the trouble of reading it and just tell you this -- the criteria are derived from an algorithm built around a 70/30 service facility orientation and are the only inspection body who stays anonymously. That said, Forbes’ guide is available online at ForbesTravelGuide.com totally free, and is more comprehensive than the AAA system.