Is it productive to use a Stylus with the iPad? My son loves drawing comics.  He wants to do it now on my iPad 3.  Does anyone have experience with using a Stylus for such an activity?

Does it make sense or will it be an exercise in futility?  I've looked at the Wacom Bamboo and Cosmonaut stylus.  Are either of these (or some other ones) suitable for drawing comics?
The Cosmonaut is about the only stylus worth the effort in my opinion. I've tried a few different ones, but the Cosmo' has always felt right. I think it's to do with it's weighting and general sturdy feel.

I think with practice your son will produce excellent results using the Cosmonaut, especially with the right app (Paper or Sketchbook Pro are excellent for art.)

--

'Random' 2yr update: After using the Cosmonaut on and off for the last couple of years, mainly with Paper by 53 and Procreate, I feel a small update is in order. 

I've used the stylus with the iPad 3, iPad 4, iPad mini and iPad Air. I've noticed a gradual loss of effectiveness of the stylus - it feels harder to use resistance-wise than it used to. Could be a change in screen surface technology or just the wear-and-tear you'd expect from using a stylus. So my opinion of this has lessened to a degree. Perhaps Paper's 'Pencil' product will be the one for me, when it's finally available for non-silly money in the UK.