I own 4 Ti-lites.
The folding stiletto has been my favorite style of knife since I was a child. For decades I was only interested in the more traditional Italian stiletto (back lock, guard bolsters). When I learned about the Ti-lite I refused to buy one because they aren't "traditional".
But eventually I became curious enough to try one. I was very impressed and encouraged by some torture test videos of the Ti-lites I had watched. So I started with the Ti-lite 4 (zytel handle). It was one of the sharpest knives out of the box I have ever received. I wasn't able to wrist-flick it open due to the deep detent hole, which was a negative for me, but after some modding I solved that issue.
Then I tried the Ti-lite 6 (zytel handle). Immediately after taking it out of the box and wrist-flicking it open the first time, it became my all-time favorite knife.
The T6Z, even with a snug pivot, easily wrist flicked open due to a shallow detent, and the weight of the blade. The lockup was solid. It was not as sharp as the T4 due to the thicker blade and the steeper grind.
I have since purchased 2 more Ti-lite 6's with zytel handles. So far 2 of the 3 I own have been heavily modified to suit my tastes. My T4 has also been heavily modified.
I've handled an aluminum handle T6, and a G10 T6, but I found them stiff to open (couldn't wrist flick them). I believe the reason is due to the bead-blasted surface of the aluminum handle T6, and the black coating of the G10 T6 causing friction in the pivot. The zytel handle T6 has a satin finish blade.
I carry both my T4 and a T6 daily. I find the T4 works great for simple utility cutting.
Due to it's size, the thickness of the blade, the strength of the lock and solid lockup, and the ability to easily wrist-flick it open, I consider the Ti-lite 6 with zytel handle to be the ultimate production folding stiletto available today.