I don't see any point in shooting RAW Robin, I have no intention of using my pictures for prints any time soon and you have to be an expert to notice the quality deterioration between RAW and JPEG. Even heavily cropped shots don't really show up on tinternet. I use Aperture like you. Try taking a pic in both JPEG high quality and RAW then magnify the focus point 100 times you won't see any difference. It is only when you start printing that you need to be looking at RAW in my opinion.
....Although that is true, the reason I prefer RAW is that the files have far more data - Much less of the captured data is lost directly from the camera body's sensor. The reason I prefer the option of holding that data is that it's far easier to enhance an image after uploading. Aperture has good RAW fine tuning and
IF you need to go further then save a 16-bit TIFF and edit further in Photoshop. You can Save-for-Web as a JPEG or at any stage which suits you.
It can depend on the photographic subject too - The finer details of bird plumage and Dragonfly wings etc etc are beneficial to enhance and when needed make corrections to. You might have captured a really great unrepeatable moment but the image leaves much to be desired but then editing in RAW might just rescue it.... or not! Et voila, you have a 65Mb file!
I started off with my DSLR in December and shot everything in both JPEG and RAW, then only JPEG and shot a couple of images which I loved but needed editing and was limited. So, encouraged and advised by a few serious and pro toggers I now only shoot RAW (and now need a mahoosive external HD to store them on!).
I guess that discovering what a modern digital camera is actually capturing encourages me to exploit it even though I have yet to print a photo! My images are all for online use so far. A couple of people (who really don't know any better) have suggested I produce a wildlife calendar but they obviously haven't fully appreciated the standard of what's out there!
However, the bottom line is the 'workflow' (or 'playflow') which each of us enjoys the most and we are all different.
I'd be interested in what both Ian (Hedge) and Rich (wig) think about shooting in RAW. Also the views of other serious photographers here, especially professionals.