i suggest yo to follow these page i thank it will help full for you (AIR-SAP vs AIR-CAP)https://supportforums.cisco.com/discussion/11723671/air-sap-vs-air-cap
HI Jemel SantiagoLOAD BALANCING OPTIONS:How network hosts are assigned to each GLBP router can be altered by using one of four load balancing options outlined below. Please note, theseoptions are not able to be deployed concurrently. There is a negli...