vgrove, I use my Diners Club card a lot more than the Sheraton Optima, recently I've been only using the Sheraton Optima at Hiltons where an AMEX card is required for the double mile/pts promotion.

The Westin Visa gave 2 Westin pts per dollar (translates to 0.4 Starpoints per dollar versus the 1 Starpoint per dollar for the Optima) - I don't know what the status of this card is.