i use a mix. for some models i use acrylics (most matt models and some figures) and enamels for others. i was doing a figure the otherday and i used a mix on the person. i find pots of enamels tend to last longer e.g. i have had a 14ml pot of 19 red for therly 6 years now and it is just entering the to replace farily soon stage.
so the chioce is up to you and what your preferencis are. i tend to use actylics becuse you can wash theh brushes in water.
each paint in my opinionn have there ups and downs so its up to the modeler