Yes, you can pull up hotels by category: in the pop-up window that appears showing the number of points for a free night per category (
http://www.marriott.com/rewards/poin...dType=Standard), there a box in the top right that says 'View hotels in each category'. Just select the category number and click on the 'Find' button.
I tried to switch from the 15 night/25,000 points promo (which there is no way I'll
ever make) to the cert one, even though it's a tad underwhelming. Unsuccessful so far, but I've decided to be stubborn about it...