Look around at the awesome baths that are available now. They are just not for plonking the body in to cleanse. They are for pampering and romance and candles....you get the drift. No luxury spa would be complete without an self standing soaker.
If you've got rid of the kids think of yourself. It's the hotel room at home. Back rest plus book...heaven.

for the size of the house I would recommend a tub in the master bath.

Tub! Just don't get one so big that it takes 2 hours to fill up! Separate shower.

We love how routinely this subject comes up... Hopefully you are please with the choice you made on your project... [we'd love to get your vote in our poll on the subject. <<---(Green i s link) [(https://www.houzz.com/discussions/tubs-vs-showers-the-great-debate-dsvw-vd~2984090)

We put a tub and separate shower in and never used the tub. Do what works for your family. If there is a tub in another bathroom, there is no need for an unused tub in your master.