Just hit it today (with my usual shaft, ventus black 6X and grip, oversized specs) on course in some obscenely windy weather...
I’m finding no discernible differences in distance on the course (can’t speak to ball speed, but judging by the distances prob similar enough) between the EFSZ and tsi3, and that’s with the tsi loft at 9 (which is between .5-1.5 lower than I normally play, and giving me a somewhat lower than ideal ball flight).
I think I’ll be able to get the TSi3 going significantly further (for me) once I play with the loft and some lead tape. It wasn’t the distance which impressed me though, it was the actual size of the sweet spot - definitely felt like a larger area on the face had the ball going max distance.
I would guess that something in the epic speed line would probably have the same distance and similar forgiveness for me, you, and many others. That said, this club looks and sounds so good, and being from Latrobe, I have to love the Pittsburgh-made ATI face. As such, the only thing that might kick this out would be the TSi4, and I’m not good enough or patient enough to wait for that.