There are free alternatives out there. I haven't tried Notebook Assistant to be able to compare, but Grok seems to do a pretty good job. For example, prior to the recent lunar eclipse I asked it to write a Mathematica function that would allow me to input a time and date and output a map of the current location with an arrow pointing to the direction of the moon. It gave me exactly what I wanted. One might say that's a simple application, but it seems on about the same level of complexity as the examples I've seen.

From comment - "Bottom line: the current iteration of Notebook Assistant is a pricy toy rather than a practical tool for most WL users."

Totally agree with you - I am a Hobbyist, been using Mathematica for approx. 20 years - I immediately "invested" in the annual subscription Notebook Assistant on release in December and could not get it to give me any meaningful result without syntax errors - very disappointed.

As a MINIMUM requirement - Notebook Assistant SHOULD return code the works and does NOT have syntax errors. I also subscribe to ChatGPT Plus and Gemini advanced to help me with my coding and syntax errors - Both of those were working better than Wolframs Notebook Assistant to correct syntax and produce working code. That said I recently upgraded to Mathematica 14.2 and the Notebook Assistant is working better. So glad other people have been feeling similar frustration...

I expected that an expensive paid additional add-on like Wolfram's Notebook Assistant would have produced perfect syntax error free code - initially I was very disappointed, but I think it maybe better now - let's see...

George and others. Of course, the so-called hallucinations are problems that must be brought to an absolute minimum. Unlike some people, I have a lot of patience to put up with obvious errors and find a way of getting at the truth. How do I know the difference? I don't always, but fortunately hallucinations don't seem to be based in difficulty! Sometimes, I can ask a competing Ai in a different context. Sometimes ask another for a proof while putting it off as my own naive idea. Sometimes do a little research. Sometimes the hallucination just makes no sense!

As far as "reasoning limitations go," like proving something clearly provable, but I've never seen written out and am too lazy to think of on my own, giving the Notebook assistant hints from my best reasoning as I go and asking for a step or two at a time seems to work well so far.

Here is an example of where we both just had to hold each other's hand to scratch out a proof that was sufficient for me: