With the VOLMET you can usually obtain a recent destination METAR (often with TREND forecast) over half an hour before landing. This gives you time to insert figures into the FMS in level flight, and conduct the pre-descent briefing.
ATIS is often unreadable until you are well into the descent, particularly in mountainous areas like northern Italy. Although it should be fresher than the VOLMET - and provide info of the duty runway and any major unservicabilities - they rarely give a trend forecast.
The pilot who is copying a semi-audible ATIS in the descent can easily find himself out of the loop when he has completed the task.