Legal Question in Real Estate Law in California

I'm not following why you are interested in doing an AITD if you are putting down a large down payment. The main problem with AITD's is that most underlying deeds of trust that the seller already has require the loan to be paid off if the property is sold or transferred. Under an AITD the seller effectively loans you the original loan plus something, records the AITD to secure his interest, and deeds the property to you. That will trigger a due on sale clause and put the whole thing into default. Plus, even if you don't have a due on sale clause in the seller's original loan, you have to count on the seller to continue making the payments on his loan out of the money you pay him. If he doesn't, you get foreclosed. The way to avoid that is to set up an escrow account, make the monthly payements to them, and they divide it between the seller and the original loan. But that involves fees from the escrow company. SO back to my original question. Why do an AITD if you have the money for a down payment?