Thanks! Good to know the JW Marriott Essex House handicap rooms were nice. I've stayed in a few, mostly because of last-minute check-ins when there has been no other available rooms and sometimes the handicap rooms are not all that nice, beyond the accommodating bathrooms. But that's mainly been at lower-end properties on road trips, aka La Quinta, Best Western.
From what I understand we will have to be mindful of ensuring that the room has a walk-in shower rather than a tub-shower combo, though most of the tub-shower combo rooms I've experienced have been in older, cheaper properties that had not yet been renovated.

Do you know if some hotels will be able to provide a shower seat? I've seen some built into the showers of handicap rooms.