Thanks for the responses. I have found SPG availability to be excellent. I can think of only one time that a Starwood hotel had rooms for sale but no award availability (they had 1 higher level room available and no points rooms--I can't really complain in that case). It is sometimes frustrating when I wanted a nicer room or a suite and it wasn't available for points, but there was still the option of booking a basic room.
My Marriott experience, while a very small sample--hence my request to see what others were experiencing--has been very different.
Has anyone stopped using their Starwood Amex card and shifted to a different card?
The programs remain separate. I will continue to use my SPG American Express product.