Steve Jobs of Apple was famously quoted in 2010 "If you see a stylus, they blew it" when talking about stylus and handheld devices. Anything separate from a device is subject to failure, simply being lost, forgotten or broken. I think Steve is right.
However, I did consider what benefits a stylus might bring to the user experience and explored using some software called DocAS for capturing my notes on an iPad, during meetings etc.
The mobile phone stylus worked brilliantly, more accurate than using a finger and makes handwriting directly on the screen possible. There are adjustments you can make to the thickness of the writing which is important.
DocAS allows you to open a PDF document on the iPad screen and simply add sketches or diagrams directly onto the screen. Annotations are added in the same way.
The usual functions are possible, saving / exporting / printing as you would expect in any iOS software.
The stylus has a soft nib which makes contact with the screen. The material used means that the iPad's screen is very well protected and won't get scratched. The stylus is also very light, so doesn't add very much to the overall weight of carrying iPad and accessories
My initial view was not to bother with a stylus device, but I think having played with one, it certainly has its uses. I often attend conferences and workshops and where to put notes following these events is troublesome. Having all my notes stored in one place, particularly if these accompany the presentation slides or briefing document. I'll be requesting the presentation slides ahead of the talk from now on!