Just a comment about the tub. You have to sit in it while the water drains. There is the issue of being chilly while that happens unless you add a heat source above. I would also worry about accessibility ,ability to recline , the ease of an assistant bathing you and quick egress in an emergency
I am not yet in a wheelchair and I love my accessible shower. There is a pull down bench (which can later be used by a caregiver) and grab bars all over the place. Shower on one side and hand shower on the other side. Easy to get in and out both by foot and with roll-in shower chair.