Harbor Court Hotel is the best around, IMHO, and the Inn at Henderson's Wharf at Fells Point by the water taxi is a great experience and excellent value in an old converted tobacco warehouse with a free light breakfast ala B&B style included. They used to also offer see an PO's game and/or decent wine & dinner deals at nearby restaurants so I'd ask if interested.

But for obtaining miles & points, I agree that the REN is probably your best choice. Unless I'm mistaken, this used to once be the Stouffer Harborplace.