For the OP:

This is one of the FT posts where I have learned a few tips. As many of the respondents already mention, the SPG Amex card offers very good value for both miles transfer and hotel options.

However, as a frequent traveler, I find that Marriott hotels are very good for airport hotel stays and i really do enjoy the Ritz Carlton Club floor. I have had the Ritz Carlton Visa card now for two years and while it is pricey at $395 a year, it does offer Marriott and Ritz Gold status which includes free breakfast, free wifi, and access to Marriott Clubs if available. I have also successfully utilized the annual $300 airline benefit (used for upgrades), and the Ritz Carlton Club upgrades which depending on the hotel and the length of stay are well worth the annual fee. It includes a Priority Club pass which I have used a few times for free airline club access when there was no loyalty airline club available. Finally, I received 140,000 hotel points for a sign-up bonus so it's been a good option so far.