Excelent RAW Primer Duncan.
I would agree that if you have got the lenses (cash) so that you don't need to crop significantly, and if you can guarantee the exposure then shooting in RAW doesn't give much advantage over high quality .jpp. That said on my camera (Minolta A2) HQ jpgs come out at ~8Mb v RAW ant 10Mb so the space saving on a card in not great.
In his book Real World Camera Raw, Bruce Frazer advocates over exposing for the highlights (very slightly - ~1/4 - 1/2 stop) which is contrary to conventional digital exposure wisdom, and then bringing the highlight detail back in your converter as a way of enhancing shadow detail.
Any post processing treatment distroys pixel values. Therefore the more that you start with the less image degredation. One of the benefits of RAW is that one can convert to 16 bit images rather than 8 bit so even the basic act of applying levels will result in less noise etc.
As Duncan says, a lot depends on the final output medium - if its 800 x 600 for web viewing the difference is probably indetectable, but at prints of A4 its a different matter. If the Pirelli calender boys (or girls) are converting to B&W then they are throwing away a lot of their captured data anyway so there is probably no point in them shooting in Raw.
I use ARC via bridge and the small post processing time penalty is worth it for the flexibility (to me
at least)