in the end nothing, they are both soap.
non gelled will have a creamy look to it, may have to leave in the mold a day or two longer as it may be softer initially. depending on formula and water discount , may need longer cure time to help evaporate excess liquid.
gelled soaps have a opaque look to them. gelled milk soaps may be darker in color then their ungelled counterparts, due to the heat given off during the gel process, carmelizing the sugars in the milk, honey can do this also.
like the method you use to make soap, it is a personnel preference. sometimes no matter how hard you try to stop a soap from gelling it will anyway, and making sure your soaps gell all the way thru so you don't end up with that ring in the middle of your bar can be just as taxing.
barb