Getting ready to do a full atf exchange in my 08 Taurus w/ 24K miles. Doing a pan drop w/new filter and cooler exchange procedure then adding a Magnafine filter. O'Reily's has Royal Purple Max ATF for $10.99qt. and Amsoil is $9.95qt. at a local garage. Is the RP really that good if the old saying "you get what you pay for" line is true? From a factual pov which is better, RP atf or Amsoil atf ?