Tri suit (all in one v 2 piece / short sleeved /sleeveless top)

Tan2

Hi I am wanting to but my first tri suit / two piece tri top and shorts. I get nervy re toilets during big events and so think I???m settled on two piece, but what???s better short sleeved or sleeveless? I see a lot on cycling stages wearing short sleeved but I prefer to run wearing sleeveless? Is it just personal preference? I???ve not seen a cyclist in sleeveless before really. Thanks tan