In most Spanish bars the gents is a normal household type toilet. The sort we men leave the seat up on. In some places, like cinemas, shopping centres or motorway service stations there will be stalls and, usually, a row of urinals too.
Personally I prefer urinals. Less chance of unintended spillage. My experience though is that Spanish men don't. They choose to use the stalls and a lot of them neglect to lock the door. This can cause a degree of embarrassment from time to time. ¡Uuff; perdón!
I wonder why the preference?