My old TB gelding Louie who is a very round 17.1 hands hates it. My newer gray 16.2 hand TB Vinnie wears the same size as Louie and is happy in the TSF dressage girth.
The anatomical girth comparison thread on the Horse Grooming Supplies forum is mine. 
I loved the Total Saddle Fit girth at first but have found now that the pressure distribution is uneven. Mine doesn’t fully gape at the front but it is much tighter at the rear and I can’t see how that is comfortable for my horse. It is sad because the price and squishiness of the padding are great! As said, not every product works for every horse.
I adjust the back billets a hole longer than the front billets and my TSF works fine for my Fjord mare with no gaping. It got the nod of approval from my saddle fitter.
I have a tendency to ride with a somewhat loose girth, so maybe I would notice an issue if that weren’t the case.
I got my TSF girth 2 weeks ago and it seems to be working out quite nicely. No gaps on my 17h TB gelding, and it works with his forward girth channel. I would caution against the County Logic - that leather getsincredibly stiff (despite conditioning), and with the squared corners can easily poke/rub a horse. Maybe I just got a bad apple, but I was very disappointed in the CL and love the TSF.
My rotund 13hh pony loves his TSC girth.
I use it with his Prestige Lucky saddle.
We tried 3 different girths and this was the best one for him.
