Should I upgrade the master bath on my occupied Rental Property

[Aaron Gorum]

To start, I have great tenant that have lived in the house since Jun 2015. They always talk about how they love the place and don't want to leave. They have never been late on rent and treat the home as their own. The husband even does small fixes around the house without getting the handyman involved "to save me some money." We have sent them little Christmas gifts each year, gift cards for a date. Now they've asked if we would consider upgrading the master bath shower. I always wanted to do it, when I was living there, it would improve the property value, but should I do it while its occupied? Thanks for any advice.