What do you consider small? Measurements would be helpful.

I would keep a tub for resale if its the only bathroom in the house. That would be a problem for people with kids or who intend to have them.
Have you looked into the wet room concept?

How many bedrooms in this house>

2 bed/1 bath.

It's good you are thinking ahead for resale if this is not your "forever house" We just spent two years looking for a house and a number of homes we viewed were customized so specifically for the owners, even if we lived in them for the rest of our lives, it would have been impossible or not affordable to "fix" them. That being said---what's the demographic of your neighborhood? Who would your potential buyers be down the road? When my son was small, I wouldn't look at a house without a tub---I had to have one for his nightly bath. Once he was about ten or eleven and started to shower, it wouldn't have mattered (DH and I aren't "tubbers"), and now that he is out of the house, the house we actually bought has three full baths but only one tub, and I'd just as soon not have that, as tubs are a pain to clean and all our bugs seem to go there to die (we live in the bug capital!). Plus, as I have gotten older, I love having a big shower that I could put a teak stool in so it's easy to shave my legs! But if you are marketing to families with young kids---go for the shower/tub set-up.

Are you familiar with this? Personally, I have never used the tub in the house. When we downsize, (after breaking my ankle) I want to get in and out easily, no tub and no shower lip.

A separation between the bathing and vanity area would be ideal especially if that is the only bathroom in the house.