Depends what motor you're talking.
IIRC, The HEI is by far the easiest way to go on the I-6.
TFI is the easiest and cheapest on the AMC V8.
HEI might not necessarily be more "dependable," because although there are fewer items to go bad, that one item is relatively expensive. TFI spreads out the possible oops, but also replacement costs; most are easy junkyard finds.
As for performance comparison, it's pretty much a wash.