Well, the answer - as before - is "It depends ...".
Whether to use one large disk or multiple smaller disks depends on the data structure. If you cannot split the data into e.g. departments, projects, home/profile, ... you may be better off with a single large disk. Remember that this will require to use a GPT partition table, and you'll need to check whether e.g. your backup software can handle this. Some image/VM based backup applications can backup and restore such virtual disks just fine, but lack the ability for file level restore! Also keep in mind that - in case of a disaster - restoring such a large virtual disk will take a significant amount of time, during which data isn't available to the users. If the data structure allows to distribute it to multiple virtual disks (you can still use DFS to present the data through a single share), I'd prefer this over the large virtual disk. With smaller virtual disks you will certainly have to monitor each of them for free disk space, but on the other hand you can increase the disk sizes individually and restoring a single virtual disk can be done much quicker (with the other disks still online/available for the users).
André