The advantage is speed and also not risking incorrect matches due to mistakes by tfm's matching algorithm. The same reasons why it is recommended to use force film vs using an auto ivtc method when dvd2avi/dgindex report 100% film or a very high percentage film. In my tests on the movie castaway tfm ran about 6 to 7 times faster than when it had to actually calculate matches. In terms of raw numbers it jumped from about 130-150 fps to 1000-1100 fps. In cases where dvd2avi/dgindex report 100% film there is still no advantage to using tivtc, but in cases where it is <100 you get the benefit of flagged ivtc in most of it (assuming it all works correctly of course
) and intelligent handling in the rest. TIVTC will still be slower than force film since tdecimate still does metric calculations, but tdecimate is extremely fast now for material that is mod 16 width/height since the isse optimized code for that path was added.