In most cases (ST with IT tail pattern) the tail bars connect at some point (like this fish or mine) something that doesn't happen with ITs and even if a 3 bar IT is stable 24/7, in my opinion, the coloration/contrast will not be as nice as the one found in a ST.
That being said, if giving the choice between a classic ST and one with IT tail pattern (same quality, same price) I would go for the classic one.