A larger shower can look appealing, and so can a freestanding tub. In many bathrooms, choosing one affects the space available for the other, the vanity, and storage.
Start with who uses the room and what they actually need. Think about your usual routine rather than the occasional use you hope to make of a new feature.
Draw the complete room
Include doors, drawers, towel storage, and the space needed to move around. A fixture may fit on the drawing while leaving an awkward route beside it.
Ask what changes to the existing layout would involve. Moving or changing fixtures needs a clear installation scope, not just a new product selection.
Consider cleaning and everyday access
Look at the areas around and behind the proposed fixtures. Ask how they will be reached for cleaning and maintenance. Review comfort and access needs with the designer too.
A good choice may be a better version of the current layout rather than a larger feature. The bathroom should work for the people using it every day, with enough space left for everything else they need.