I'm a designer and have a lot of construction experience. I think that you need to ask youself the question would you use a tub enough and is cost a factor. Having a big shower is nice. my personal bath has a shower only. Clear glass walls. makes your room seem bigger. climbing in a shower is easier than a tub. most people only use a jacuzzi tub once a year. That's a lot of wasted money. But, if you had the room a seprate shower and tub is the best case. A tub vs shower in a master is not likley to make or break the sale of your house. good luck