Hi Roger
This is very good news and it is also great that you took the time to canvas opinions. Thanks.
I have looked at your links and make the following comments.
The set up panel in the second link looks good and it is interesting to read the strategies for detecting robot submission. I suspect that some of these if included in your implementation will generate some support emails but that their omission may do the same.
From my point of view: given that all us EEC people have to comply with some form of Disability & Discrimination law as it applies to legibility of content and controls on websites, means that the noise and font controls are very important. (Compounded by the lack of audio support (for now.)
I see that case sensitivity defaults to false but it might be useful to have an exposed setting for this.
If captcha settings where implemented as in your second link I would be very happy.
This might also help other developers to use this control instead of the various lesser ones in use right now.
Finally
I was really pleased to see that your significant contributions and brain have led to your joining the core team.
Cheers
Ian