The only regret I have about the walk-in tub I bought a year-and-a-half ago is that I didn't buy it 8 years ago, when my husband first was unable to use a regular tub.
The obvious advantage of a walk-in is that you don't have to step over the side of the tub to get in and out. This is a very useful feature for a large number of impairments, or simply old age when we aren't as agile as we used to be.
But at least as important is a less obvious advantage. You do not sit on the tub's floor, but on a built in seat. Most tubs have these at a height that meets ADA standards. Those of you who have not yet reached a certain age may not think of this, but it is much, much easier to stand up from sitting on a chair than to stand up from sitting on the floor!
My husband has loved this tub since we put it in. Now on hospice and unable to walk more than a few feet, he is still asking for tub baths and still able to take them. We wheel him up to the tub, he takes two or three steps, turns, and sits down. The reverse for getting out.
I love the tub, too. I had the foresight to have a light installed over it, and I sit and read in swirling water. Very relaxing!
These tubs are expensive, no doubt about that. The sooner you put one in, the longer you will have to enjoy it. Anybody planning a retirement home, or upgrades for a parent's home should really consider this option, in my opinion.
While we were at it, we also replaced the toilet with a taller model, which is easier to rise from and sit down on. That is a good investment, too, if you need to replace a toilet.