We are doing a gut remodel and I am trying to choose between an under mount vs drop in tub installation. It’s a tight space with 60inch width total and our tub is 36 inch wide (Kohler Underscore). Unfortunately we cannot make the space any bigger without shrinking the shower (non negotiable).

My contractor says if we do the undermount we need to choose some type of slab and we cannot use tile on top (we selected a 24 x 48 timeless onyx tile). If we do the drop in installation we’d build a shelf for soap.

What is the better option for us here? What would you choose?