I have combined in main bath and separate in master bath. I like being able to step out of the shower easier than stepping out of the tub shower. But then again, I'm above the AARP age.

My master bathroom has a large shower and no bath and the other two bedrooms have bath/shower combinations. This is our preference.

Over the next few months, we will be remodeling 2 bathrooms. In our main bathroom, we will combine the current separate shower/tub. Then I can use the space from the shower for a storage cabinet, which will be great as I live in a older home with limited storage. In our master BR remodel, we will add a larger shower stall, with no threshold for aging in place, no tub in the master.

Do you use a tub? If so, I would keep them separate. If you do not use your tub, eliminate it and have a large shower (yea for the roll-in suggestion!) My theory on big bath tubs is that realtors say you need one to sell you house. That's why everyone has one. The only time it's useful is for resale. Of course, I have to admit that I use my tub all the time. I have a handheld shower in it for washing my hair. My husband uses the shower. If you decide on both, don't enclose them with solid walls. Use tempered glass to keep them more open. You'll get used to the fishbowl feel. Same goes for combined, keep it as large and open as possible. It's no fun for me to soak when I feel like I'm in a little cave. I'm starting to sound quite claustrophobic...

Master should have them separate, but other bathrooms can have a combo or separated. It depends on the home owner and their personal usage of the space. A lot of people have forgoing the bathtub altogether and only having a shower.