So I am FAR from an expert but at the matches I shoot there are us mere mortals and then what I call the "supershooters". Most of them are running 1.25" straight blanks in the 24" to 27" range that are threaded specifically for a tuner. These are the same guys ditching their TTs for other triggers because the timing is leaving accuracy on the table
. Full disclosure I am a barely middle of the pack shooter and I promise you my barrel length, trigger, scope, et al are not the weak link. I am the weak link.
P.S. Running 20" MTUs on both my Vudoos and couldn't be happier. Well, almost... I can't quite get the balance where I want it and I think the extra 2" of MTU proflie would hit my supposed sweet spot but it's a very minor gripe and on the clock I forget all about it!