I have two work stations, one uses wide gamut monitors, the other regular sRGB monitors.
aRGB is useful only if:
You only shoot RAW or aRGB JPEG and convert/process in a fully profile aware program that also supports wide gamut, or works in wide gamut.
Your doing very colour and detail critical work, and whole work flow including the end users understands aRGB
You understand aRGB, why its different from sRGB and the full implications of what that means.
You out put to aRGB (remember the vast majority of printers are not even full sRGB and can't get close to aRGB, especially commercial printers).
This is why I have the two set ups.
The work station for one business deals with RAW files only and some of the work is colour and detail critical, and I do occasionally get customers who understand aRGB.
The other work station handles a mixture of RAW and sRGB JPEG's, its total out put is to sRGB printers and while the work is colour critical, its important to keep it consistent with sRGB right trough the work flow (converting sRGB to display on an aRGB monitor can do bad things to how the file looks, causing you to make adjustments you don't need to, which makes the prints look really, really bad. I learned that the hard way.).