The only advantages that I can see, and I admit that I am not an authority on this, begin at age 65. 

At age 65 you can split RRIF income between spouses so both spouses have the same income.  This reduces income tax paid. 

http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns300-350/314/q6-eng.html

At age 65 you can claim a $2000 pension credit deduction on RRIF income if it is not transferred to another RRIF or RRSP. 

http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns300-350/314/lgbl-eng.html

Beyond this I am not sure. 

Are there any other people out there that can add to this?  I am curious myself.