how much better is the kuzma 4 point then my TTW Jelco

I measured it very carefully.  The answer is 4.

It all depends on your personal definition of "HUGE difference". 

Let's put it this way ... the 4Point and the Durand Talea were the two arms I used when when developing my new drive system.

The 4Point has a different presentation than the Talea, and it runs the possibility of revealing flaws elsewhere in your system that could easily drive you nuts.

Feel free to contact me about these or other arms (with the usual "I'm a manufacturer / dealer disclaimer).

Cheers,
Thom @ Galibier Design

I would choose Kuzma 4Point assuming your turntable will allow it to be mounted.  

I have owned several tonearms. A walker linear, a Reed 2a and 3P, a few VPI's, Durand Talea and a kuzma 4 points to name most. While I no longer own the 4 point it was/is an exceptional tonearm. Once mounted, easily set up and adjust to great accuracy. A pleasure to tweak. Only bested, in my view, by the Durand. The kuzma 4 points will give you continuous years of enjoyment. Only down side is it can be difficult to mount. As was the case for me. On my table it had to be mounted in the second tonarm position. I simplified and no longer use two arms. 
I'm just saying ✌️🖖