Hi Weary,
I feel your question has already been answered at length but here's my 2 cents:
At my station (Thales operated), the MSAW function is turned off, due to the large number of incorrect alarms. There are many situations here when an acft may decent below minimum radar terrain such as visual approaches. We tend to hold quite a bit of stock in the CLAMs (Clearance Limit Adherance Monitor). A lot less invasive (just a yellow block around the lable) and pretty effective, providing of course you keep your lables up to date...
No sirens or whistles, it just draws the ATCO's attention to it, we can then assess and react accordingly.