There are some very real advantages in the RAW format, some applicable if your idea is postprocess the image (as the possibility to save it as 16-bit TIFF, to keep all the info intact), but also some very useful even if you plan to generate a JPEG as a final image without further postprocessing. The most useful features in that case are the exposure compensation and the WB selection, because they allow you to correct some problems very difficult to corrrect in the final JPEG.
Exposure compensation is possible because RAW files store information beyond white and black points, so you can recover blown highlights using negative compensations, and some shadow details using positive ones. That is not possible to do in JPEG, because the info is already discarded during the JPEG creation.
With WB something similar happens. You can correct the colors using the extra info present in blacks and whites and still get realistic colors. Also WB setttings are very easily and predictably changed in the RAW file without any image degradation, but once the color image is generated (as the JPEG or TIFF one), an acurate color correction becomes much more difficult and usualy generates unnatural color casts.
Of course you also have all the image parameters available to tweak if you want, as color saturation, colorspace, contrast, sharpening, etc., so if you want to change contrast to low in a pictura taken at normal, you can change it before conversion. This feature actually allows you to only worry about the "photographic" settings of the camera, as shutter speed, aperture, ISO sensitivity, etc, and not to worry about image parameters during the shooting, because you can choose them in a picure by picture basis during conversion.
AdobeRGB vs sRGB is a different beast. You can use both colorspaces in RAW or JPEG, and I prefer to use AdobeRGB because it's larger gammut allow a better representation of very saturated colors.
AdobeRGB is more suited for postprocessing, as you need a AdobeRGB calibrated program to see the real colors, and sRGB is more suited for general use or the final output after postprocessing, because it's the colorspace used by printers, monitors and the web. Again, if you use RAW, you can choose during conversion if you want to generate a sRGB or AdobeRGB image, depending of the future use of it.