We are going with a freestanding in our new master bath both because we like the looks and also with our layout it worked better. Given the cost of a good tiling job I'm not sure a built-in would have been less expensive than a standalone. We had 2 drop-in tubs (one to be removed with shower stall) and one of them still in-- acrylic-- which we put in 12 years ago and somewhat regret now because it flexes and the grout cracked over time so it has needed a lot of maintenance. (this is mostly because of the material we chose). But when our kids were younger they loved the bubbles!

The WetStyle f/s tub has a removable tray that sits across the tub. I like numberjunkie's idea of a shelf or ledge behind the tub for placing items and also like the idea of having the shower wall next to the tub tiled half-way up to have a space for installing a grab bar. WetStyle has an optional shelf that surrounds the tub, but I think it would make it more challenging to get in and out of the tub - would need to hop over the shelf. The drop-in tub I was initially considering was 72"x42" but that would likely not fit, so would need to be 72"x36". This weekend I looked at an open house (new construction) in my area that had a drop-in tub with a narrow space for the deck surround (see attached photo). The deck was tiled on the top and on the apron with white subway tile. I noticed that with the narrow deck space (about 2") and the tub overhang, it would be awkward to sit on the edge of the tub and swing my legs in or out of the tub. Wiithout space for a deck that is wide enough to comfortably sit on, ease of entry or exit may come down to depth of the tub and options for placement of grab bars. The Wetstyle tub is 22" deep; the drop-in tubs are generally deeper, more like 26"

Initially, my designer recommended placing the free-standing tub filler off-center, in the corner, at the end of the tub (where my feet go) and it was plumbed that way. Then the designer changed her mind, and decided that the faucets should be centered at the end -- so I paid for plumber and tile setter to make the change. I considered having the faucets placed behind the tub, between the back wall and the tub, which would make it easier to add water when I'm in the tub, but then I would need to reach over the tub to fill it before entering. And designer said it's best to "show off" the exposed pipes on the filler. I just realized that there are black "spots" on my tub -- paw prints from the 10-year old cat I adopted this summer -- luckily, her prints wash off easily.

You need to actually need to go sit in one I love to bathe but in noway can I see that being comfortable. I also do not think a cast iron would be very easy to carry and install. IMO a nice deep soaking tub not free standing is a much better choice. Have you actually tried getting in and out of a free standing tub most are really awkward. This definately is a thing to test drive and you will need all the plumbing to be visible so expensive too.