Yes, I definitely LOVE my 23mm STF brush. It's one of my absolute favorite synthetics. Do you know if there's a way to buy just the STF knot by itself? Because if I could snag the 25mm knots, wow that'd be great.
Yes, you can get the STF knots from @Rudy Vey
So I picked up a TurnNShave tuxedo, quartermoon, full moon, and Silversynth, all 26mm knots; the full moon because it is the closest to a Duro knot you can still find and I love the Duro, and the Silversynth because it's just an awesome all-around great performer.
Fantastic!
Please compare the silver synth to the full moon once you've used them.