If you have the means, I would do separate tub/shower, too. I LOVE it when I find those in a rental, because if I want a bath in what is also used as a shower, I feel like I have to scour the tub before I'll use it.
Now that I've read that last sentence, I'm not sure it makes sense, but it's how I think about it, and it has made the difference in re-renting.
I agree, NoHall! I definitely prefer the master tub and shower to be separate. If it is combined it makes it feel like you're

I think a tub/shower combo in the guest room is good for the kids.
A third guest could do just a stand-up shower.
My $.02
