As you said,pre EMI option is good when completion of project is far away i.e 1.5 to 2 years.So that builder will have to meet the deadlines.But if you are going to possess the flat/house within 7 to 8 months period and the project is nearing completion,it is better to choose ADF option.In this case we normally have to give 80% money to builder from bank assuming most of the work completed.In this case,The difference between EMI and pre-EMI will not be much.So why extra money for the 7 or 8 months which won't be included in your EMI amount.