The most significant difference is the depth of massage you achieve with each of the balls:
Myofascial massage balls with spikes: Spiked balls will make the massage deeper especially on larger muscle groups. They also have a better effect on harder tissues.
Lacrosse balls for massage: This product is used for softer massages, where it is not necessary to have depth in the pressure they generate on the body. Actually, the type of exercises does not vary with Lacrosse balls, so both types of massagers are 100% recommended.