Vinyl Shower Floor ?

I am now starting to think about the future design of the hallway bath.  My friend wants to convert it to a shower "bathroom" which is fine with me.  But do we go with a prefab shower box (I'm thinking not) or make a custom shower on site (this is what I'm thinking).

One way to have custom shower is to have the entire bathroom floor covered with the same covering (usually 1" square or hex tile) as in the shower.  I like this unified floor idea, but in my version I would have vinyl flooring, as I think it gives better slip resistance.

Here is Tarkett talking about this kind of thing, vinyl "wet room" floors.