I wondered if a TSi4 would be coming. I know the TSi3 is the more traditional shape and will offer lower spin compared to the TSi2, but I can't see it being a spin killer like the TS4 was marketed.I think that was as much to do with loft as it was head, but in our testing I don't think either head is insanely low spin. Over the last 36 hours I have taken an insane amount of swings with the two heads. I love the fairways and will add to that thread shortly, but the drivers are an enigma to me so far.
They look, sound and feel downright perfect. The shaping at setup is confidence inspiring and classic. The sound at impact is really REALLY good. I get decent numbers out of both of them, and when they are compared loft to loft, the spin was slightly lower for me out of the TSi 3, at about 250 rpms when I average them out. Neither really go super low spin, but that could be dialed in with loft generally speaking assuming launch is okay.
Based on conforming list and timing of previous launch, I think those searching for that, will hold off and see if they release the TSi 4 and 1 later on.
Like you I really like the look and from all the videos the sound and feel seem to be really good also. I get the sense this line (more than any other previous OEM offering) will need a proper fitting and you won't be able to fit blindly based on the previous version.