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"

I love my tub. It feels very solid, but it was installed on a mortar base per the manufacturer's installation instructions. You can do a search for Kohler 5' archer and open the manufacturer's website link. They have a file you can download that has complete installation instructions and complete specs. It does have some sort of nonskid texture on the bottom of the tub. It is very comfortable to me. Mine is the whirlpool with the in-line heater. I don't have any regrets with my choice. Something I really like is the horizontal overflow. That allows for more water depth, yet the step over height is only 19 inches.

Sheridan Meltsner, thank you so much! I don't know why Wayfair doesn't use the "Cube" name, but that's the tub. It says 6 - 8 weeks for delivery, so I wonder if they typically order from Kohler and have it shipped directly instead of having it in stock. I'll ask our builder to follow up. Kudzu9, our builder recommended two NG tankless water heaters, one on either side of the house. We think that arrangement will be better than the two 75 gal. NG water heaters we have in our current home. Our current master bath tub is a large Kohler Vintage and we had to add additional support beneath the floor when it was installed. I guess that's one benefit of doing an insulated slab on grade at the new house.

Being able to sit on the ledge, swing your legs around and then get in is a huge plus - as is the ability to have a towel, candle, adult beverage, book, phone, etc. nearby and not have to use a tray or the like. Also - not crawling around the back of anything is more practical. I see absolutely nothing wrong with your installation preference. Your architect / designer pushing you to a "style" that doens't meet your needs isn't cool. Unless you were building a spec house - your personal preferences need to be incorporated and expanded upon for a god outcome FOR YOU!